if a guy find it easy to talk and be around one girl, but then when he is around another girl he does not know what to say and cannot look her in the face straight? when he approach her, he is either rude, or short mouth. or sometime he is grinning to wide and cannot really stay and talk with her a good 5 minutes. but he finds it easy to talk with another girl and be her friend.

why he cannot do the same with her?