Aita

AITA for refusing to babysit my sister’s kids after she called me lazy?

My older sister constantly asks me to babysit her two kids for free. I’ve helped her dozens of times without complaining because I love my nieces and nephews. Last week, I told her I couldn’t because I already had plans. She got upset and said I was “lazy” and that family should always come first.

The next day she asked again, and I refused. Now my parents think I’m being petty and should just let it go since she’s stressed. I feel bad, but I also don’t think it’s fair to insult me and still expect free help.

AITA for saying no?