it will be the same as a college party without the highschool girls showing up.
just get a keg and some liquor. my bro is 26 and his roomates are about his age give or take a year or two, and they threw a party about a month ago. it was pretty much what any college party would be, w/people their age and also a little older and a little younger, but no highschool girls ...
just like college parties w/out the HS girls 🙂