I had the reputation as "the meanest mom in town". But guess where all of the neighborhood kids came to play!!! I had rules and they were followed by everyone. If someone didn't follow the rules and nobody told me, they all got in trouble. Guilty by association. So they learned to police themselves. As my kids got into High School my house continued to be the gathering place. I think the kids (and their parents) knew that it would be a safe place (no drugs or alcohol and lots of supervision). Now that my youngest is leaving, there are younger kids wondering where they will go for "after prom parties" because we have had them here for 8 years! By the way, we do not have a big house. The room they gathered in is about 10 x 15 and there would be 20 - 25 kids playing board games or watching movies. I am not a perfect parent, but I encourage you to continue having his friend over but make sure he follows the same rules your own child has to follow!