I would not go. I like to keep my distance with this kind of thing. I don't need them to think we were friends, and I don't like them getting close either. I know from experience that even though you really like all the dc families now six months from now something happened and you kick them out now they can go and bad mouth you to the hole dc. If your in a small town or community that means word will spread fast and now your having a hard time finding kids. As for the birthday thing I have a small party at dc so kids can have friends to celebrate with but no parents. If the kids birthday is on the weekend the have the dc party on the Friday before.