When someone tries to pass as heterosexual (married, kids, etc.) but everything about them screams homosexual. Perhaps the person knows that he/she is gay but is denying his/her impulses (for whatever reason). Or, perhaps, they are not in tune with their inner gayness and do not realize their true nature.
I would swear that my hair dresser, Jack, is gay. However, he's married with a kid. I still swear he's gay. I guess he's heteroquestionable.