I was 17, definitely a late starter among my friends.
It was a ONS with a female friend of another friend I was visiting who was at university at the time, who kind of set us up.
I lied and said it wasn't my first time, but it very quickly (pun intended) became apparent that it was!
I am genuinely ashamed that I lied like that, even though she said afterwards she still would have agreed if she had known, but would have been expecting it!
So no, I would have much preferred to have a different experience altho it didn't bother me that it was a ONS with a stranger.