Before I found Jemima, I met up with a couple around my age and I was willing to become a third with them, but they lived to far away, and to be honest, I was attracted to the girl but not her boyfriend. If I had gone with them instead of Jemima, would I have then fit the terminology?
That said, I was never really keen to join an established couple. I didn't want to be the third wheel, there to make their relationship more interesting / better. I wanted us to all start at the same place.
Sorry, I'm not trying to be a unicorn haha, I'm just new to this whole thing and am trying to get my head around the terminology.
As for girls and boys as opposed to men and women - I don't know anyone my age, students especially, who talk about "men and women". None of my friends would say, "I'm looking for a nice man" or "look at that attractive man". It's always boy or guy. We reserve the use of "man" and "woman" for people that are a lot older than us. I don't know if this is a student thing, or a New Zealand thing, but here, it's not said. Too young.