I like a boy. He is an amateur pas de deux and has a female partner. When we first met, I didn’t have any feelings for him, but then I liked him more and more, and I was a little bit annoyed.

Since this is the career of the person you choose, you should have the awareness to accept it.

Also, if I were you, I would jokingly ask him about his relationship with this girl, and then jokingly and seriously tell him "I will be jealous." If the two of you are confirmed to be in a relationship, then I should talk to him clearly and give him trust. Then if it were me, I would make friends with that girl and tell her that I love boys when we are having fun. Anyway, that's probably it...