Ok lol I'm not sure where everyone got the idea it was about a baby shower.
I went to a baby shower 1 week after our wedding and it WAS all girls and I did not ask him to come along.
The event in question is actually my HS reunion, 10 yr reunion next spring.
I know he struggles with group settings, especially strangers, so I gave him a head's up. We had our wedding in June and then a few weeks after we were all settled in I brought it up casually "you know, all my hard work to get a tan and do my hair and buy a nice dress I won't have to worry about it again until next April". And he was like "why is that?" "oh because that's my 10 year reunion. Now I'll have a cute husband to come along

"
And he didn't object then.... but a week later he was like "Can I be honest? I thought about it, and I really don't want to go".
And it was after a day of kind of not agreeing on some things.
So I thought he was just sore about something else, but after we resolved that he still doesn't want to go.
So I asked my mom, who'd been heavily involved in helping me succeed throughout school, so I figured she'd want to see me go. "Am I a bad person if I don't go to my reunion?" And she said "I never went to any of mine. It will mostly be the kids who drink and party and didn't care about you in school there."
So I thought about it and realized most of my friends WERE either one year ahead, one year behind, or from another school entirely.
In this case, both my husband and my mom MAY be right. I don't NEED to go. But there are some things that he turns down that I think are important, like social functions involving our church, and I need help discerning when it's best to try and cajole him anyway.
"Come on sweetie, I know it's not your favorite thing ever but it's good for us. boosts morale. I'll treat ya to sushi after?"
and when it's best to be like "you know what? you're right. Let's do something you want to do instead".