Most Helpful Guy
Can't say.. guys like those never change. If they are in live with you you will be only one who he will be keeping quiet.
Most Helpful Girl
I think that his behavior to others is also important because anytime he can behave you the way he behaved the other. You ca try dating him but you must be very cautious about him. You never know what might pop up in his head. Also if he is a great manipulator dont you think he behaves you the same but you just do not see it? Just take care! I would take double attention to him.