I think it was during one of those parties when I was 8 years old. We would all be in a room and then switch the lights off, then everyone would bump into each other etc etc... Anyway this girl I kinda liked bumped into me and I kissed her and she returned the kiss.
But that may not be the first, but this is the one I remember best
But that may not be the first, but this is the one I remember best