It was at my old after-school care in North Sydney, I was 7. We were playing "Let's Pretend" and this girl and I had to pretend to be boyfriend and girlfriend. She took me behind a tree and said because we were the boyfriend and girlfriend we had to kiss. So on her count, we pecked on the lips- twice.
As for my first "Kiss" (i.e hooking up), it was at schoolies last year late one night with this chick from Yamba. I was pissed and it didn't last very long, but it made me realise that unless you're in love with them, it's overrated. :|