I (41/m) was doing my favorite uncle duty (babysitting!) and everything was going swimmingly.

It’s getting close to bed time so I tell my niece (6yo) she has to get ready for bed. She says she has to take a bath and needs help and asks if I can give her a bath.

This would be our first bath time since she was a baby and that was really different. So I said “sure but let’s finishing coloring this page first”, and then it was “let’s have a piece of fruit” and more delays (roughly an hour and a half) until the parents came home. SIL was annoyed that child was awake and not bathed and I explained (out of earshot of my niece) that I didn’t feel right giving her a bath.

Today I was talking to my brother and he said his wife is a little annoyed and I should be prepared to hear about it. I explained that “bath time with my uncle” could be a topic of therapy in 20 years and I want no part of that. He laughed and called me a dork.

AITAH for ignoring my SILs wishes (bathed and in bed by 8:30 pm)? Should I even defend my choice here or just accept that the parent is right?