You will never know where you stand. He will give you the world in one moment and pull away the next.
He will be the most attentive creature for a while, then disappear.
Even if you try to have ‘the talk’ with him, he will find some excuse why he can’t be in a committed relationship, he will probably blame the timing or a past relationship.
He will be good at sweet-talking you into staying hooked on him but he won’t show any signs he wants you to be his girlfriend so be careful not to fall under his spell.