When a person bangs another person in that same gender, except they are still "in the closet" about it; secretive, in denial out in the open.
Noun: Literally a "Bone in the closet".
(Names of the following are fictitious and any relation of the two are coincidental)
Steve is attracted to Bret in an intensely sexual way but since he's a self centered douche and cares mostly about his reputation they're going to Bone in the closet.
First person: "I opened the door and there was something catching flies in there and it' smells awful. What was it?"
Second person:" . . .@$#*! Yeah, that's just a bone in the closet."