What does it mean when a guy is flirting with you but he already have a girlfriend and does it mean he a player?

Don't be flattered. Basically he: 1 ) is testing out the waters to see if you'd be interested in hooking up with him behind his girlfriend's back. 2) believes you're the type of individual that's fine with flirting and possibly hooking up with guys who are already in relationships. 3) isn't mentioning a Word of this flirtation to his girlfriend. All in all, not a classy way to act towards his girlfriend or you. He probably feels guilty about breaking up with her or is not sure yet but still wants to "test out the waters" to push him that step forward and to see if what he is flirting with might be better. (but that is a rare case, you could probably tell if he is that type of guy anyway)