Am I the asshole

My birthday is on Friday and I wanted to do something. Either with my fiance or a friend. I'm a stay at home mom. I really just wanted out without my two kiddos, just for a few hours . Anyways, my fiance asks me if we wanted to see a movie that night. I said sure, that sounds great! Then he said his mom could watch our 1.5 year old and we could just take our 6 year old.

I told him that no, I really didn't want to take her with us Friday at the movies. He got upset and I asked him if he understood where I was coming from.

Even thoughe said yes. He was visibly annoyed. We can be apart from a six year old for a movie date, it will be fine. I don't get any free time for me or us. Why he would want to bring her is beyond me.

Especially because we could always take her on any other day.