"Grown ups do grown up things together"

My husband was offered 2 free tickets to a football game, we love football. He came home told me, then said he didn't take them because there was only 2, so his son couldn't go. His son is only 6 and has no interest in football what so ever. I feel like it's normal that grown ups go out and do grown up things without there children, and that's totally okay! Especially because we never do anything during the week. I feel like the fact that he has a son controls him to no end. I want to do things with my husband atleast once in while. I'm tired of spending my weekend being the 3rd wheel, doing everything they like while I just sit. I understand not going out all the time, but hell, we never do anything "because the kid can't come" i watch friends of mine with children go out, do fun things together and have fun. Why can't we?!