Not being American, I suppose I'm not totally up on how bad things have gotten over there, but I would think that most people wouldn't think too much of you having boys in your house once in a while. If it was all the time and a constant stream of 30 different boys, yeah I think that would raise some heads. In my opinion, you could just do what you do, and don't talk about it with your adult friends. If they ask, and especially if it's just one or two boys, you can say they are sons of your friend, or two friends, whatever. Hanging out with your friends kids is something that strikes me as normal for anyone, especially if your friend is a single mother. Most sane people would then see you as a hero.

But again, I'm not American, so maybe my experiences are irrelevant here.

Hikaru