Much depends on what you mean by "partying". Getting together with friends, having a few beers and watching the football game is pretty harmless. Falling down drunk kind of partying would not be okay (and is more about the falling down drunk issue than the friends as far as I'm concerned).

Let's assume the partying is more of the first type. Why is that such a problem? It's good to have other friends and interests than just your marriage/spouse/kids, etc. I think it's fairly common for adults to have get togethers with friends on sort of a traditional basis, even after marriage. I have female friends I go out with fairly regularly (once a month or so) to an event or for dinner. It's healthy. Marriage can't just be about the relationship and the kids; you are still individuals and that individuality has to be maintained or the relationship can start burning out.

But if it is wild, drunken, juvenile type of partying, no, that wouldn't fly with me. Again, that's more about the behaviors than the friends.