M.J.
I absolutely agree 100% with every word Denise said. In & of itself, a 1-time incident is just something that happens to a lot of kids, which of course doesn't make it right, but also doesn't mean they'll be scarred for life from it. I'm with her that the age difference would bother me considerably more than the act itself.
You said the incident was a few months ago but you guys get together almost every weekend so I'm just curious why you're asking about it now as though you're just now going to talk to your friends/the other parents about it sometime soon...?