My sister (34F) and I (30M) have always gotten along fairly well, but recently there’s been some tension. She’s a single mom with three young kids (6, 4, and 2), and she leans on me a lot for help - mostly babysitting. I don’t mind stepping in once in a while, but lately it’s turned into something more like a weekly expectation, and she usually gives me very little notice.

Just last week, she called me Friday afternoon asking if I could watch the kids that evening so she could go out with her friends. I told her I already had plans (I’d actually just booked a dinner out to treat myself)), and she immediately snapped. She said I was being selfish and that “family is supposed to help each other.”

I tried to explain that I do care, and I do help out, but I’m not always available on short notice. She wasn’t having it and basically implied that I was putting myself before “what matters,” and now she’s barely talking to me.

I get that she’s overwhelmed and doesn’t have a lot of support, and I truly do want to be there for her and the kids - but I also feel like I’m allowed to have my own time and plans. Just because I don’t have kids doesn’t mean I should be expected to be on-call.

AITA for standing my ground and refusing to babysit when I had other plans, or should I have just sucked it up for the sake of family?