Okay, hooking up at the prom probably isn't that unusual, however, it was at someone else's prom.
My wife attended a public H.S. I went to a Catholic all-boys school. We had mutual friends at the public H.S. who were a grade ahead of my wife.
We wound up going to their prom. The others left us at the table, she asked me to dance, and when the dance was over, she kissed me. Now, she'll swear I kissed her, BUT, she kissed me. We've been together ever since!
Over 20 years now.