Ex(s) and Ohs

Alright. Big b_tch session here...
I talked to my exhusband tonight because this weekend is his weekend to have the girls. They go to his house on Friday night and I pick them up on Sunday. It is supposed to be 6pm to 6pm. You do the math; they aren't there much.
So my oldest, Mak, is in 7th grade, which you already know. This means she is allowed to attend all of the high school functions - games, dances, etc. So this Friday is a traditional "Big Game" for our school. We play our rival school who is also in the same county as we are. It is called the Bucket Game. Long tradition of the winning team taking the bucket (pail for your n'easterners) and proudly displaying it in a showcase in the school until the next year's game. So after this big game on Friday night (think Friday Night Lights movie, folks), there is a dance that lasts until 11pm. I'm rambling...I asked the ex if Mak could attend, forcing him to drive 15 minutes one way to pick her up at the dance upon its completion. He has stated in the past that he is over the little scheduled outings on 'his time' and wants the girls to be at his house when they are supposed to be. To my surprise, he said she could go. I should be ecstatic then, right? Almost. His comment about the dance is what got me. The exchange is as follows:
Me: "The dance is over at 11 o'clock and it is in the cafeteria, right there when you pull in the high school."
Ex: "So this thing is for high schoolers, too?"
Me: "Yes, it is for both high school and jr. high."
Ex: "Well, I'm definitely not too crazy about that!"
Me: "Oh Lord. You know, most of the high schoolers think it is too dumb to go, so the people who are there are mainly jr. high kids."
Ex: "Well... I'm just sayin'..."
Me: "So she can go, or what?"
Ex: "Yeh, I guess. "
Me: " So what your saying is you'll pick her up. at 11. at the school. right outside the cafeteria. like I told you. "
Ex: "Yeah."(said in one of those 'kiss off' tones)

Conversation over. Me mad that I had to talk to him and get his point of view that makes no sense, given his input on everything up to this moment in time.
I can't win sometimes. I mean, she isn't even interested in boys (on an outward level). She goes to see what everyone else is doing and to dance (fast songs) with her friends. She is much more reserved than that. At least he could give her credit for that.
Oh. The agony. Just let me raise them. We're all better off.