Came while giving a blowjob
(This is something I have done many times since)
A few years ago with one of my boyfriends I was using a vibrator on myself. It was so fun focusing on his cock while I held the vibrator on my clit.
I definitely took my time as I was really enjoying myself. I got really close to cumming so I dialed it back and waited as my lips slid up and down his shaft. When he started to twitch a bit and I pressed the vibrator down a little more and when I felt the cum burst in my mouth it set me over the edge and I came while managing to keep stroking and sucking him. It was so satisfying to cum in unison like that. Bonus was him going down on me afterwards until he was ready to fuck me.