It's wrong to reveal someone's sexual identity without their permission.
Al is talking to his sister Lil, abut her friend Li at a lunch table.
Al wants to share something interesting abut Li.
Al says Li almost made the Olympics one time.
Al tells Lil that Li is secretly gay and does gay sex in private with gay people.
Lil gets to hear an interesting story, and Al has Al's sister's attention which is validating.
Li's privacy is invaded and Li is embarrassed for people to know these things.