Mine was at the age of 15. It was the third or fourth date I think, and we were sat on a park. It was pissing it down with rain, and she gave me a hug and started playing with my hair. She got close to me and we just kind of looked at each other for a few minutes, obviously within kissing distance, and we were both waiting for it to happen, hell we were kind of stopping ourselves but the intention was obvious. After a moment or two I said:
"So, what happens now?"
Then we kissed. Surprisingly managed to do okay considering it was my first, nothing embarrassing happened, and we shared a nice day. The next day I got a text telling me she wasn't ready for a relationship and she dumped me. But hey, it was a nice moment at the time. We were on different wavelengths anyway, it wouldn't have lasted. It was, as they say, a learning experience.