First time was happenstance, when I was 15. I was kinda nervous about starting high school the following week; the anxiety of doing so in a new town wasn’t helping anything. I was running errands with my mom one day, we’d capped off the afternoon by picking my sister up from marching band practice. She’d brought this other girl along, having offered her a ride home. I don’t really remember the specifics about the trip, just ‘ooh, meeting a new person, let’s start the “new place” jitters early’. I think this girl and my sister were chatting something vaguely along the lines of coming over for French horn lessons. I don’t remember the specifics.
Two years later though, I’d gotten into theatre. Day 1 of rehearsals for a play I was cast in, there she was again. The roles we were playing didn’t interact much on stage, so when I wasn’t playing my part, I got to spend a lot of time in the wings. Watching her, being enamored with her performance, gradually realizing I was catching feelings for her.
I made a move, eventually, we went out for a while, it was great while it lasted. But, ultimately, we made better friends than lovers. We’re still friends, or at least friendly, to this day though.
Capping off is a way to say conclusion. Like finishing off, wrapping up, things like that. Jitters are a kind of nervous feeling.