Neighbours' kids all play gun games.

My son, 5, has started to become really good friends with the kids on my row (ages ranging from 3-7, mostly boys). I don't have loads of friends with kids, so I'm really glad they get on and he has more kids to play with, but they often play gun games. This comes with two problems, not only do I think they're all too young to play such games (I find a 7 year old holding a plastic gun to a 3 year olds head and saying "I'm going to kill you" a little disconcerting), but I also refuse to buy my son a toy gun, so he cannot always join in with the games they play anyway.I don't really know what to do. I don't want to say he's not allowed to play with his friends or for him to feel left out. I've thought about talking to the parents, but I can't see any way that would turn out ok.Anyone got some advice on how to proceed? Or some arguments on why it's not that bad? I try to tell myself that it's not really any different to pretend sword fighting, which I'd feel much more comfortable with, but I still can't bring my self to be OK with toy guns.Edit: I'm bad at proof reading. via /r/Parenting http://ift.tt/2bJR5gL