Ha, cute topic.
Mine was when I was 7. It was with a neighbor who lived upstairs from me at the time, she was 9 or 10 or something like that. I had NO clue as to what the hell I was doing, but we were watching TV and there was some mushy movie on and she planted one on me. SO, I kissed her back! I really didn't know what was going on, so I tried to do what I saw on the TV and played with her hair and hugged her. Oddly enough, it s what I STILL do now when i kiss a girl, its sort of developed into an automatic thing. Kind of funny now that I think about it.