Over the weeked me, DS, DP and her DD were at an event. I brought 2 camp chairs and thought she would bring along hers. She didn't. So we had 2 between 4 of us. Anyway I didn't mind standing. Me and DS came back from the toilet and DP and her DD were sitting on the chairs. My DS sat on the floor. I politely asked DP if he could sit on the chair instead.
She got in the biggest strop. Involved her DD and told her DD to get out of the seat and they both went and sat on the floor. I said her DD was fine to sit in the seat and I didn't want her DD to move. They both wouldn't talk to us and she created a frosty atmosphere.
My DS who is 6 then went up to them both to show them something. She made a comment to him saying I thought you wanted to sit down, go on, go sit down. It was me who asked for him to sit down not him.
I jumped in here and said this comment was uncalled for and for her to stop it. I didn't get an apology for the childish behaviour.
If it were the other way around I would not have minded giving my seat up for her DD. Me and DP are adults and I don't think a fuss should be made.
AIBU to think she behaved like a bratty child?