My friend refuses to go to a "college party". We are 23. Is he being a snob?

My friend, who told me to “find something going on this weekend” for us to do saturday evening, is refusing my idea to go to a party at our alma mater and see some old friends of mine. Here’s why I think he should go:

1) We always do what he wants to do. Always. Want to go to this bar? He’ll say, “Nah, man, not in the mood, let’s go to THIS OTHER bar” He has now given me freedom to choose the evenings activities, and this is what I would like to do.

2) We always only hang out with his close friends, who are my friends too, to an extent, but really they are his crew that he grew up with. So I don’t see why he can’t come and hang out with me and some of my friends for an evening, plus he is really outgoing so it’s not like not knowing anyone should be an issue.

My friends throwing this party are 21, 22. We are 23. My friend is telling me “I’m too old for college parties, man, I’m over that stuff. Let’s find something else.” WE’RE ONE YEAR OLDER THAN THEM! I’m sorry, this is such a catty question but is he not being a snobby little prick about this? Had I told him it was just a party he would have been all in, because I go to his college-grad friends parties all the time (which are no different than the ones we went to in college, really). What would you tell this guy?