Hmm, depends on how you define it.
I was six years old and playing in the sandbox with my next door neighbor Ted (yeah you can't even make this shit up) when he asked me if I wanted to "touch tongues".
I'd never even heard of anything like that before but it sounded intriguing so I said sure.
So yep, two six-year-olds started making out in the sandbox.
It wasn't exactly passionate since neither of us had truly sexual feelings at that time but it was an interesting sensation - I still remember how his tongue felt, warm and cool and slippery at the same time.
My mom kinda freaked when I told her about it.
We moved away a couple years later - but not because of Ted, as far as I know.
Last I heard of him, he was playing linebacker on his high school football team.