Okay, I have a guy friend of mine (or, an acquaintance really), that I used to have a REALLY HUGE crush on. My feelings for him have died down... Show More
Most Helpful Opinion
First off you I can't answer this until I know the type of connection he and his girlfriend shares. Is it having a girlfriend just to have one? In that case he is in "what if" case. i.e. he is like "what if I had asked this girl out, she appreciates me so much more than my gf."
Otherwise it maybe philandering.
It may or may not be a mind game. There are two ways to make sure i) asking him and ii) studying closely the relationship he shares with his gf.