Becoming a priest, nun, or monk is a choice. Celibacy is not imposed on anyone, but those who choose it seem to get by just fine. Black people, on the other hand, do not choose to be black.
Obviously I was exaggerating for effect. But you’re exactly right, being celibate is a choice. So God creates heterosexuals and homosexuals, and he tells heterosexuals they have a choice about having sex or not having sex, and either choice is ok as long as they’re married (or not priests). He tells homosexuals they have no choice.
Sounds reasonable.