My stepgrandkids, children of SS30, 9 and 3 have spent most of the day at my house. As I posted in another thread, I refused to babysit them although I have spoken, given them cookies and interacted with them as what they are, DS7 and DH's guests.
DS7 really likes them and they like him. Sigh. If only they came without the baggage of their parents, aunt, grandmother etc. and of course, my baggage, I would have them right in the playdate rotation. But they do have that baggage which is really heavy adult baggage.
Since I set that boundary, I've noticed how much calmer they seem today. Maybe because I am very much NOT in charge of them today, maybe because they sense my detachment, there is a big difference in behavior. Maybe because they know their grandfather, DH is large and in charge. Whatever the reason, I see the difference. Maybe DH finally stepped up with them at long last. Doesn't matter because it is only for today, I think.