while you we're talking with your guy friend, Niki was watching you and he doesn't know why he suddenly got this jealousy over him. when he was about to walk out of the door, Niki suddenly held your wrist and the door suddenly closed that bumped your guy friend's head..

when you realized that Niki did that, you removed your wrist from his hand and looked at him with the "why did you do that?" look. Niki just glared at him while the guy walks away in embarrassment.