I'd also like to add that she texted my ex stating that we cannot get him earlier or keep him later because he does not just spend time with by BF, that he spends time with "all of you".

You're just getting started...way too soon to be expecting perfection. Blending families is tough stuff. While you are frustrated, surely you realize so is the child. His world has turned upside down and adjustment take time.

BM and BD may have been in an dead relationship for the last four yrs, but Mommy and Daddy have been together being Mommy and Daddy all along. His father home living in his house one minute and suddenly Daddy's living over with JenniLynn. JenniLynn has two kids too. Another adjustment. Has been a single child and now instant new kids in his 'family'. Also Daddy lives with the new kids, while he sees Daddy once a week for dinner and EOW.

This new lady cooks 'strange new food', not at all what Mommy makes ( a word of advice here, praise the boy for taking the bites he does...at least He's not griping his tummy and squealing tummy ache 'I don't feel good'). He's trying it. His dislike for whatever it is your serving is nothing personal against you. Your kids eat it and gobble it down because it is what they have always eaten and known. It's not new to them. Just keep cooking/serving what you normally do and now and then actually toss in something you know he does enjoy.

Stop doing special favors for the mother. As she has made it clear she does not intend to do Dad any favors, then BF too should just follow the court visitation 'rules' also. You can't resent doing her favors if you stop doing them. perhaps a few times of being told 'no' BM will decide to become bit more accomdating on her end. If not, oh well. Everybody can just stick to the orders. if you let her take advantage of you, you really can't be upset that you/BF said 'yes' but no favors arrive in return.

All kids seem to have a desire to turn back the clock and make their mother/father a family again. He really is not desiring anything that lots of other stepkids are. Adjustment takes time. It's been a few months. THe kid is still mourning and/or missing the family and home life that he had. If you make a huge issue of of some of the things the child is saying (example wants mom and dad and him to have dinner, get remarried) you could quite possible make the child really resent you. it could go from missing but adjusting to hating and blaming.

His father could talk to him. Not in a 'never say that again' type way but instead a acknowledgement that Dad understands things are strange and different right now, but he loves the child and will always be there for him. Blah blah blah...Dad will figure out the right things to say that assure the child things are different but will be ok.

You didn't mention anything 'bad' about the child so I'll assume you don't dislike the child, you just rather wish you could wave that magic wand and hurry up the adjustment period.

@Justmetoo - I do praise him regularly and have also incorpprated into our diet mac-n-cheese, pop tarts, and pancakes (the stuff he regularly eats). I am ever-so-proud of him when he does try something new (whether he likes it or not).

As for EVER mentioning ANYTHING negative in front of him or toward him - I would never do that. I treat him as if he were my very own child - and yes I do like him - love him like he is mine actually.

I know it may seem as though I want perfection (not realistic), I think my concern is more with the mom putting thoughts/words into his son's head - this not only concerns me as I am a mom and would never do this to my own kiddos - but the fact that she is so bitter towards us and is using his kiddo as what appears to me to be a pawn.

I just wish there was something I could do - or advice to give to my BF.

I may come off as jaded but everything in the OP sounds like a HUGE red flag... one that was waving before I married my husband and things deteriorated to what they are today. If I could go back, knowing what I know now... a lot of things would be done differently.

Unfortunately, in relationships... there are three sides to every story ~ His Story ~ Her Story ~ and the Truth. His perspective could be that things were dead for 4 years. He was there for financial reasons.... etc. Her perspective may be that they still had a chance to work it out & be a family. Regardless of having boyfriends, that doesn't indicate how someone truly feels deep down. Breaking up a family is never "simple" and children will forever want things to be better, even if they know the parents were no good together... some hope more than others, but I think if we could change things and have them the way we think we want them... but as adults, we know that's not possible but kids hang onto hope. Hope that they will get back together. Hope that they will change. My SD's parents split when she was 1. She's 13 now. I'm sure she wishes her parents were different, that she could be in a nuclear family instead of having to choose between them. She wants to live with her mom but has said she'll miss her dad. She lives here and yet, she doesn't. Of course, she is an extreme case but you get the idea... kids want attention, love and to be the center of their parent's universe. It's easier for that to be, when the parents are together. It's harder for everyone to focus on the kids when they are split up and worse, when they don't get along... and then you add step parents/siblings, etc. to the mix. So, it's really up to your BF to reassure his child of his love, yet at the same time, help him to understand that a reconciliation with his mother is not ever happening. Some kids accept it & others don't. (and remaining in the marital home, still legally married to the mom... sends a message to the child that even though he knew they weren't getting along... they stayed married for a period of time & remained living in the same home. That has got to be so tough for a child to grasp what adults are doing.)

As for the mother putting thoughts into the child's head... maybe she is, maybe she isn't. Asking him if his mom told him to say that is asking him to betray his mom... and most people would never do that, so I will assume you wouldn't. But, I have felt for the last 7 years that my SD's mom is the instigator in telling her daughter to dislike me, telling her I'm not her mom... she doesn't have to listen to me, respect me, etc. I know there's some truth to it based on things that were brought up in court & things BM has said to DH... and SD parrots those exact phrases. There is absolutely NOTHING you can do about that, except try to have a relationship with the child if the child is willing. My SD was not willing, she says 2-3 words to me a week... and she lives with us full time. It's very tense and miserable at times. She is a prime example of what happens when a mom uses her child as a pawn. As miserable as I am... I'm sure her daughter is even MORE miserable than I am & she is off focusing on her relationship with her BF & their child.

The best I can offer is to try to glance into the future & ask yourself if this is worth it? Like I said, every child is different so my outcome is really because my SD resisted having a relationship with me, no matter how hard I tried. Her loyalty to her mom is/was that strong. If your BF's child is open to a relationship or accepting of the situation, the chances are better. If he's not, then you may be in for rough ride. Your first consideration should be what you are willing to expose your kids to in order for YOU to be happy with this guy.... because he's a package deal with his son.

IMHO you guys went WAY too fast in rushing to live together, that was a huge mistake..... Sounds like he basically moved out of his marital residence and in with you...and you immediately started to blend your families. This child never got a chance to get used to the fact that daddy doesn't live with mommy anymore, and then he has a new family thrust into his life....what 6 year old would handle that without issues? JMT makes an excellent point...this kid went from seeing daddy every day, to seeing him 3 days every two weeks....but he LIVES with these other kids. That must be so hard for a kid that age to handle.

I think most people wouldn't even recommend having kids that young involved with one's BF/GF that early after starting to see them (and that soon after moving out), not to mention moving in together. My GF of 4+ years and I have decided not to blend our families (I have 50% custody of my two kids, she has full custody of her son) just to avoid all these issues. Yeah some things would be a lot easier if we lived together, and there would surely be a lot more money left over at the end of the month if we didn't have to both have a place, but in the end we feel we are doing what's best for the kids.

As for the behavioral stuff....I'd stay out of it as much as you can....he's not your kid. Leave the parenting and disciplining to your BF, it's his job. Be the child's friend. And I know what you mean about the food stuff...my GF's son is 12 and he still has so many food issues, it drives me NUTS....but I for the most part stay out of it, even though I would handle it very differently that my GF does....because, like I said, he is not my son to raise.

Welcome to the wonderful world of blended families...ugh!

You did not mention, JenniLynn, if BF spends some one on one time with the little guy during the times BF has the child. Does Dad make sure that a part of the time the child is in Dad's care, that Dad and child get some personal Father/son time?

IMO it's important to the adjustment for the child. Maybe something as simple as just Dad and son off to the park for a couple hours on Saturday. No you. No other kids. Then perhaps Sunday afternoon a group activity or a quiet afternoon with everybody just around the house or maybe a family movie. I think Dad needs to not only 'tell' son things will be ok but 'show' son that Dad is still every much a part of son's young life and very interested in spending quality time. Sometimes when families blend, between hectic schedules and a full house it is sometimes too easy to forget to take the time to show each child they are worthy of the parents time and attention as an individual.

You also did not mention the ages of your children? Do the kids all get along? Is there anything they might all have in interest that could perhaps help prompt them all to want to spend time with each other? Anything like that that you can try and come up with could help the kids begin to bond a bit.

Poptarts? Ick. Anyway, maybe Dad and son can cook a meal for the household now and then (gives them time in the kitchen together and menu will be of course some child and BF likes)

I'd think that if BM and BF lived together for a mere convient arrangement, that surely they must get along somewhat. I mean who'd live together legally separated for a year if they hated each other, right? Could they handle a co-parenting for divorced parents type class/counseling together? Obviously, if they have not 'loved' each other in like five years and basically only lived together as finacial roommates, something like that classes/sessions for them together should not cause jealous tensions. They don't like or hate each other, I'd think they could pull it together enough to try and work out issues in a manner that is in the child's best interest. If the birthmother does not even love the guy, nor did they have a marriage but in name only for so long, why do you think she is so bitter now? What reasons does she give for not wanting the child to spend time with you and your kids?

Is she really bitter, or could perhaps she just be trying to shield her son from what seems to be a very fast new instant family...one that in reality might or might not survive? yeah, I know, you love the guy and plan on spending the rest of your life with him. But I'm a realist and I know that sometimes things don't always work out that way. Second marriages (and you are not married) and blending families have a fairly high failure rate. Could it just be the rushed situation that Mom is having trouble with. She could be fearing this is one new relationship to be followed by yet another and another. Sure, you're in love and all that, but BM has no glassball to predict ex husband/your future to any exact means and reality.

Where is your own children's father? Not literally, but I mean is he involved? How often do your children see their father and how long between your own break-up before your children were moving in with this gentleman? How do they relate with BF? Or for that matter how did they adjust and how smoothly when your relationship with their father ended?

Not that any of that is my business, but tossing it out for things to reflect back on and perhaps consider in putting your new situation into perception.

@mrkroopy - actually he did move out way before us getting our home together. His son had time to adjust to daddy not being in "their" home, as well as adjust to me being in the picture way before this.

With regard to the disciplining, food issues, et al - I do stay out of that aspect of it. I DO, however, make his time here as fun as possible, i do praise him (probably more than I do my own kiddos), etc.

@justmetoo - yes, he does have one on one time with his kiddo - this was at my suggestion. He is also involved in his son's school activities, as well as sets aside 30 to 45 minutes every night to call his son - which I think is awesome! (I wish my mom would have been that involved in my life as a young child).

All 3 kiddos get along wonderfully - it was like they had always been around each other (well minus the first week here visit). They are amazing together and all have like interests - I -so far - have only seen that his son gets a little saddened when my daughter leaves the house to go play with her friends in the neighborhood - maybe a little jealousy, idk!

As for BM and BF - they got along somewhat - he had it easy while living there in that he worked and was barely home - when he got home he spent that time with his son and put him to bed every night and then went his own way in the house drowning himself in work or friends. For the most part, when I entered the picture they seemed to have a working relationship - but as time has went on i have noticed that she is becoming more and more bitter. I have tried to take her out for coffee (just to get to know one another) and she wants no part of it. As for the possible fear she may have - I am the only woman he has dated whereas she has had atleast 3 that we know of (men - bf's) in and out of her and their sons life in the past year. So i really don't know.

I have been single for 7 years before meeting him, and their dad is semi-involved - plus he lives across the country which makes it hard for him to physically be in the picture all the time. My kiddos were young when we split, and I am very open and honest (to an extent) with them about pretty much everything. They know that me and their dad were and always will be friends and the adore my bf as he does them.

I have tried to look at all angles - which is what brought me to this post. I like to think that I am open-minded when it comes to rough situations, but this has me baffled. I don't want anything to derail what is otherwise a beautiful relationship all around.

I just want to make his son's life easier as I truly do believe that his mom is putting all these crazy ideas in his head and having him repeat them back over here - which I absolutely think is immature as he is a child and should not have to worry about anything other than being happy. As for her, I just wish i knew how to handle her, how I could be a positive person in this picture in her eyes.

So perhaps that is still why the bitterness is developing. Mom is dating, trying to find a new gentleman. She's failing to find a suitable new potential partner (or actually taking her time to choose well?). Been through three in a year. But Dad found is new partner instantly and has preceded to be happy, acquire a home and seems to have a perfect new life.

Several things: Mom's attempts have not yet been successful, she may believe because she is not yet found a new mate, that it's only a matter of time before Dad's attempt perhaps fails. (I'm not saying it will, I'm saying who knows what is going on in Mom's way of thinking)

Two, she may be resenting that while she is looking but failing, her son is already involved in Dad's 'new family'...this could threaten her sense of well being in her mind that son might enjoy Dad's family too much and replace her own mom role (again, not saying you are trying to replace his mother, but it is possible Mom believes you are or that son will 'like you better')

Three, it's also possible Mom is struggling to maintain her previous lifestyle. Surely if not her income, the amount of monthly cost on her shoulders has risen since Dad moved out. She could be becoming bitter over thinking Dad/JenniLynn is appearing to have a grand life while she struggles to pay her mortgage or ________ (fill in the blank).

Coffee with the exwife? Oh, no, no, no. Come on, I get that you mean it in a let's co-parent your son in a co-effort of his best interest now that I am his stepmother type way...but you are NOT the co-parent, Dad is. Don't force yourself in this lady's face...don't make her feel you are a co-parent in te raising of HER child. Any working anything out must be between the actual parents. Show me one mother anywhere who would gladly and willingly want her role as mother taken away from her and replaced by another woman if she is the primary residence and raises her child 24/7 roughly 25 days a month. Your advice and suggestions may someday be valued and appreciated but don't force yourself into what she deems her role as parent of her child. World War 3 will hit your doorstep! She shares the child with Dad, not with you. If Mom, Dad and perhaps you joined together for a coffe meeting, that might be ok...if Dad and Mom meet in person to discuss the child, that is ok...but don't expect the mother to come have coffee with Dad's GF to discuss her son. (yes, I know you're more than a GF, you're living together and you help Dad with the child on his days, but bottomline, you are not married to the son's father. even if you were, Dad is the parent, you are Dad's partner not the child's co-parent)

It's different in that, yes, you are a part of dad's life. You assist in some caretaking. You might even do some of the dirty work of raising a child like cuddling him while kid barfs...but you are not his mother and while hopefully a mother can appreciate the caretaking of her ill child in her absence, she will not welcome you calling her up and telling her how to raise her child on a daily basis. Dad and Mom are the co-parenting. She is not going to see you as an equal with a right to automatically have say in how she raises her son. You would not be caring for child at all if you were not living with the father. The co-parenting has to come between the parents.

I know it becomes very hard to not take on a true mother/son relationship when one takes on the child/children of a new partner. Afterall, the child/children lives in your home blah blah blah...but it is essential that Dad do the majority of caretaking and decision making while child is in his home and also between the BM and himself.

Don't let husband push what is his role onto you. Even though you appear to be taking it on quite willingly and trying to be the best stepmother you can be along with loving the child and having concerns for what you believe to be the child's best interest. It's Dad's role to be the second parent to the child and his role to communicate and co-parent with the child's other parent, the mother. If you become the middle guy and/or you become the one appearing to be the co-parent the mother could very well go out on a full anti-you campaign. You could perhaps become a threat, if only in her own mind.

It's a delicate juggle. If she's threatened by you or belives you are overstepping your role/boundaries in her child's life, she could become more resentful and really begin trying to poison the child against you.

@justmetoo - that's just it - I do NOT want to step in and be a co-parent to their child. I have my own that I "co-parent". I have spoken with her on numerous occasions (mostly on the phone) and she has mentioned that we do not know one another - my attempts at coffee and/or lunch was for both of us to get to know one another as two females. To give her the face-front opportunity to see the type of person that is around her son, I even suggested a play date at a local park just her, me and our kiddos. In my mind, this is to set her mind (as a mother) at ease. My goal - is to have a happy, "working", functional relationship with her.

She did express to me once that she feared a close-relationship between her son and I but then followed that up with - "i know you will never replace me" and I assured her that that was not my intention. As for money problems - she has absolutely NONE. Financially, she is way better off than me and the bf.

I love the advice you have given about the "co-parenting" - again this is not my intention or what i believe I am doing. Another reason for posting is TO GET ADVICE - I have never had to step into a role of being a caretaker (so to speak) of someone else's child/ren other than my own - this is new territory for me - not to mention the transition that bf and I have had to make and go through on our journey with ourselves. I have always been independent, the sole-decision maker, etc., and now sharing those responsibilities with him.

I know there is not manual on being in a relationship (whether first, marriage, etc.,) but because bf and I have a strong bond - and because we will be getting married - I first want US to have an idea/opinions on how to handle not only situations that will affect us, but also our children. I hope this makes sense - first cup of coffee this am - so brain is not fully functional.

I guess, in essence, I'd like to have it to where both households have a friendship all around, I do not want to be best friends with her, but I'd like there to be a mutual respect for one another. I can see the bitterness getting worse and just want to nip it in the butt before it turns not only our home into a nightmare, but my main concern is his son, and my kiddos.

I have read some horror stories on here and other sites and I do not want it to get to that.

While YOU may think the little guy has had time to adjust, the child may not think so. While parents may realize that the marriage was in trouble, he may not have. He may also resent sharing his dad with your kids. You are quick to call this kid spoiled -- yet are asking him to share his dad with your kids. You talk about how you get along great with your ex, but he seems uninvolved, and certainly there is no SM stepping in.

I think YOU should see a counselor --I dont see you showing empathy for the little guy.

"actually he did move out way before us getting our home together. His son had time to adjust to daddy not being in "their" home, as well as adjust to me being in the picture way before this"

Unless I am missing something the OP said I am still not sure how this can be possible...based on what she said. "Going out for a year" and "moving in together 4 months ago" is no way enough time for the kid to adjust to what's going on .... but what do i know......

Exactly, Mkroopy, what KK is pointing out. That perhaps JLynn is not looking at the whole thing in manner of how the child sees it or how it affects the child.

Labeling the child 'spoiled' and automatically seeing the 'problem' as 'single child syndrome' was directly contradicted by --"All 3 kiddos get along wonderfully - it was like they had always been around each other (well minus the first week here visit). They are amazing together"--

Obviously not a child who was not taught to get along with other children, not one who has trouble sharing nor one who feels he is 'special'.

I think it's possible there is a lot of comparison going on between the children and it's unrealistic. I don't think it's on purpose, but it's not 'helping' the situation. These children were all raised by different parents in different homelife settings. How the two act, or accepted this or that has nothing to do with how the little guy should then too be acting nor the timeline he should be expected to 'fall in line and get over it' so to say.

Also, because JLynn has not had to basically 'share' her children in a weekly back and forth manner, I don't think she quite grasps what this is like for the children and parents who do. Suggestions of coffee meetings and playdates between the two ladies and all the children, I think rather points this out well.

It's too late to go back now (the moving in and house buying together has already occurred) but it's not too late to readjust the attitude of it all. Which is what I think KK tried to point out. If it's advice JLynn wants, IMO she is recieving some excellent, just not perhaps what she expected or wanted to hear. The adults in this scenario have played a bigger part of the 'problem' than any of the children have. By setting unrealistic expectations, over stepping boundaries, and thriving towards instant harmony and perfection.

I'm back to my original advice. Let the co-parents do the co-parenting. Realize that this is a six yr old little boy who has had life drastic changes in a very short time frame and do not take it all as a personal afront to you. Be glad that the child gets along with your children. Be glad that the child does not dislike you. Remember he has two active parents...and let them do the parenting.

I definitely had NO EXPECTATIONS of what to hear - hence the wanting advice - and thank you ALL for it!

While I do agree that my attitude toward his son may be one of disengaged - that is not my main concern, yes it was #1 issue listed - but my MAIN concern is the ex-wife making life miserable, putting ideas, suggestions, etc into her 6 year olds head - advice on how myself to deal with it as well as advice for my bf on suggestions, avenues, etc on how to deal with it. It is driving him insane as well.

I get the whole concentration on the "children", but honestly I cannot foresee life being easy at the rate his ex is going - and yes it WILL effect her son as well as my kiddos. My goal is to nip the problem (the adults) in the butt and save any major trauma in the future - if any of this makes sense at all.

"but my MAIN concern is the ex-wife making life miserable"

You are not going to be able to "nip it" by yourself. Unless the ex starts to realize how it's hurting or affecting her child, she is probably not going to be motivated to change at all. Hearing it from you or your BF (and sometimes even the kids) doesn't usually help. In fact, it can make it worse. (ie. "how dare they tell me what is best for MY child!" or she could get the idea that anything her kid says to her is coached by dad or you.

The best thing you can do is ignore it. When kiddo says things you think he heard at mom's... you (or preferably dad) can smile & say, "that's nice dear" and change the subject. If he tells you things that aren't true... smile & say, "oh, that's not true" or "that's silly honey, that didn't happen." and change the subject. and don't let the ex get a reaction from your side. As long as she gets a reaction or has some say in your home, she will continue to do what she's doing. If you ignore her, eventually she will get tired or involved in her own life and hopefully stop.

Thank you imamommy.

My second issues: His ex-wife...to me she seems extremely bitter - which confuses the heck out of me because if they have had a "dead relationship" for over 4 years - she shouldn't be bitter and she has also had a few bf's since I have been in the picture

You should not believe everything a man tells you about the relationship between him and his previous wife. Even though their 'marriage' was over 4 years before divorcing doesn't change that they JUST got divorced.

I am quite concerned that you two moved your families in together so soon after him moving out. He didn't even have time with his son to adjust his son to his new life and circumstance. Of course a child at that age dreams of nothing more than their parents being together. It's all he has known his entire little life. Shame on dad for moving so fast despite his child.

Quoting JMT

I'd think that if BM and BF lived together for a mere convient arrangement, that surely they must get along somewhat. I mean who'd live together legally separated for a year if they hated each other, right? Could they handle a co-parenting for divorced parents type class/counseling together? Obviously, if they have not 'loved' each other in like five years and basically only lived together as finacial roommates,

Exactly my point. My ex and I were married for 5 years. Our relationship was divorce worthy for 2. Legally seperated for 1. We lived together. We were sharing the bed, not just for sleeping purposes ;), bathrooms, finances, dinner, tv. Just like a married couple. He swears he slept on the couch for a year. That actually never happened. But that is what he likes to tell his new wife.....

Now that I have completely read the entire thread, I have one more comment.

As far as mom putting things in the kids head. Maybe take a step back and look through a different set of glasses. This may not be mom's doing. He is 6. My dd was saying these things to me and to her dad at age 6 and NO one was saying them to her. She is now 11 and told me just the other day, 'I wish you and my dad could love each other'. It was completely out of the blue. We have been divorced for 6 almost 7 years and it's been quite a while since she has said anything like this. She did go further to tell me that she is grateful for my dh and for her little brother but that she just sometimes wished our family was normal. I think maybe a 6 yr old talking about mom and dad together is very normal and does not mean mom is telling him to say these things. The things you would be seeing from a 6 year old if their mom was telling them things would be actual actions and not words. He isn't going to remember to recite word for word what mom said to say to dad's new girl friend. He would be angry at you, disrespectful and he would not at all listen to what you say. And he would be distant with his dad. Those are signs of parental alienation. The child would be so pulled and would shy away from affection from dad if this were happening. Sounds like he just has a lot of memories that he wants to share.

In the very beginning of my divorce. I was bitter. My ex had met one lady and they moved so fast. (they are married now). I dated here and there. My friends set me up, I met a guy through work. I even got in to a relationship that ended badly. I did feel like something was wrong with me. How did this man go on and find someone to fall in love with, to move in with, start a new life with and I was just still searching. Sure it's silly to an outsider but according to my therapist I am a very normal person with very normal feelings. What made me even bitter was the new woman was wanting to 'get to know me so that I would know who was caring for my daughter'. I didn't want to know her or what she had that I didn't. Yup, that's insecurity and again very normal. My ex was back and forth back and forth. We'd sleep together and then he would go back to her two days later. She never knew any of this but I was bitter and she pegged me as the crazy ex wife that wasn't over her man. Yup, I wasn't over my husband, my ex husband, my marriage, my divorce, my family, my broken home but he was but not really because he couldn't stay put. It was very hard and after a couple of years I met a wonderful man and I'm very happy with my life however there is still that little pang of, my daughter has two mom's. When she was born I never Invisioned that. Had I known, maybe I would have held her more or maybe I would have taken more pictures. Maybe I would have watched her sleep more because I would have known that I would miss many nights of having her in the next room. Divorce is hard on everyone and just because someone still has feelings and might seem bitter doesn't make them a bad person or crazy. I didn't want to hang out and have coffee with this new person. I didn't want her in my face. I didnt want her to answer the phone when I called because I surely was not calling to talk to her. I don't think I would have felt that bitterness at all had she just let me be and stay out of my co-parenting. She thought (maybe she thought I don't know) that I wanted to know what my daughter was doing when I wasn't around and honestly no, I didn't want to know. I was better off being blind and dumb but she thought she needed to inform me because she was just trying to let me know what kind of nice person she was. Nope I didn't want to know. And I really think had she just stepped back and stopped rubbing her new little life in my face, I could have just been blissfully ignorant and not felt bitter.

I bet if you just step back and not even show yourself at all to her, that bitterness will die down. Don't answer the phone when she calls. Don't do pick up or drop off. Don't send emails. Just be your BF's girlfriend and the mom to your kids. Be kind to his son and love him be there for him and she will see that she didn't need to be bitter and her insecurities were unfounded. It took me a year or two to realize that I am in control of me and my relationship with my daughter is about me and me alone. I am the only one that can ruin what we have. But it does take time after a divorce to feel secure in that. I felt like a failure in many areas. But after a while I realized I am not.