Some of my friends are married with kids, some are married without kids, and some are single. My wife strongly prefers hosting couples and not my indidividual friends, so they dinners are my friend plus his wife/gf who no one knows as well, and I never really like that awkward dynamic where he and I are the only people who really know each other. But she understandably doesn't like 3rd-wheeling it with just me and the friend alone. So we mostly only ever have friends over who are married, unless it's someone we're both friends with.