| If his name isn't on your lease, that might give you some leverage, bcs you could use "telling the landlord" as leverage. I can understand why splitting the rent 3 ways might seem unfair to her, since it's not like a 3BR apartment; she's thinking that she's sharing HER space, and the only thing that changes is the mount of electricity being used, or whatever (though, if you're being not being charged for hot water, I bet the electrical bill doesn't change much). But I also think she can't have an extra person in there for the same amount of money. Because unless he spends all his time in the bedroom, then she is also sharing YOUR space with him. (are you splitting it halvies right now? What way does she compensate you for her having the bigger room? When I had the bigger room, it was because I had paid the full security deposit and the last month's rent; my roomie didn't; I also had the full lease responsibility, and she didn't; also she had major use of the living room bcs I did crafts and stuff in my bedroom) Is there somewhere between halvies and thirds? rent is $1150; half is $575; third is $383. What if the big bedroom becomes $650, and the little bedroom is $500? They split the big one, you pay for the little one. The thing is, maybe she COULD get a 1BR for $750, but it would be a major pain, plus she'd have to pay for breaking the lease, even if it was only her half. And if she breaks her lease, maybe it would be harder to get a 1BR. One point you can make is that, w/ him living there (and really this has been a problem all along, but now it's official and sanctioned--which means that now there is no "doing her favors by putting up with it" and in fact, it's time for her to start paying you back for the favor you did her all these months), that means the use of the SHARED space is more crowded. You're less likely to find yourself w/ the living room to yourself now and then, because 3 people will be using it; even if she works late one night, he'll be likely to be home (this will be true for all of you, but you're not in the "family unit"); she'll never be out for a little while because she's visiting her boyfriend; they'll live in the living room instead of her occasionally "living" in the bedroom, which she might be more likely to do if he weren't there. When they're both home, they'll be talking to each other, instead of her talking w/ you, or nobody talking at all. I've never known in what happens in a two-names-on-the-lease situation. What if she wants to break the lease and you don't? Is the whole lease broken, whether you want it to be or not? If so, what recourse do you have in terms of her agreement with you--small claims court? If she wants out, then can you get another roommate to take her place on the lease? That might be the best--to speak to the landlord to see if you can take over the lease, or replace her with someone else. Frankly, I would NOT want to live with someone and their boyfriend. Talk about feeling like an outsider, in your own home! She's changing the rules, bigtime, and probably you should have said something long ago, even before you moved in together, about what the agreement would be in terms of boyfriends staying over, etc. You *should* have told her you had a problem w/ him living with you, if only so you'd have a bargaining chip. (and in fact, you actually DO have a problem w/ him living with you) This is one reason why the landlord I had back when I shared an apartment would not put 2 names on the lease. My name was on the lease, and I was responsible for the rent, etc., w/ permission to have a roommate. best of luck And the lesson for us all--set up rules on this sort of thing before you even agree to go apartment hunting with one another. | 
