Come out of the closet
Definition 1 of 2
Pro Tip 1/3Cultural Sensitivity
Understand that revealing one's sexuality can carry significant emotional weight and risks. 
Before he came out of the closet, he considered his family's attitudes towards homosexuality.
Pro Tip 2/3Personal Choice
It's a personal decision; the phrase should be used respecting someone's choice to share or not. 
It's not our place to say when someone else should come out of the closet.
Pro Tip 3/3Privacy Respect
Use the phrase considering the individual's privacy and the context of the conversation. 
Respect his privacy; don't discuss his coming out of the closet without his consent.