I (28F) am getting married soon and have been planning for over a year. I’ve always made it clear to my sister (30F) that I didn’t want kids at the wedding because it's an adults-only event. I explained this a few times, and she agreed.

However, a few days ago, she casually mentioned that she’s bringing her two kids anyway because she doesn’t have anyone to watch them. I was frustrated and reminded her that I specifically asked her not to bring them. She said I was being unreasonable and that I should “let it go” since her kids are well-behaved.

I stuck to my boundaries and said no. She’s now upset, saying I’m being harsh and that I’m not being a good sister by excluding her kids. AITA for sticking to my rule?