Dabbler
A straight guy who occasionally sleeps with other guys, just to feel cool. His wife thinks it's a phase. His friends think it's a hobby.
'I told my wife I was going to the gym, but I was actually at a bar with my guy friend.'
'He said he was bi, but he only dates guys on weekends. The rest of the time, he's with me.'
'He told his boss he was working late, but he was actually at a strip club with his coworker.'