I don't class myself as a kid either and I'm sure there are a lot of people on here who consider themselves grown, but I think he just meant it in a friendly way. Like how some people say "right guys!" even when the group includes women.
Yes. I thought I'd try to sound a little fun/friendly, so I said kids instead of guys. I was trying to write with a little flair. I'm sorry if I hurt your feelings, next time I'll go for a more stiff approach.