Two difference.

Argument.

Later in 10 minutes after Meggy left, SMG4 entered the kitchen and looked around for SMG3. The room was completely dark due to early sunshine, so 4 decided to call out for 3.

SMG4: SMG3? Where are y-
SMG3: Right here.

4 turned the light and seen SMG3 standing near the table and staring at SMG4 with a completely calm expression. 4 decided to come closer to him, SMG3 then walked a little backwards from him, almost feeling the wall by his back.

SMG4: Are you ok? Meggy said you left after the movie.
SMG3: Uh..the movie just sucked, that's all.
SMG4: Oh, yeah, a bit so.

SMG4 knew he was lying, but had to accept his answer to avoid the trigger, as he knew how easy it is to piss him off, but decided to try to ask about his real mood.

SMG4: You...seem to be stressed. You sure y-
SMG3: Yes I'm fine. Why you gotta be that curious about that? Even if I would be stressed, I wouldn't ask you helping me.
SMG4: Hey, you never acted like this before, and I'm worried, I am your friend after all.
SMG3: Friend..say, if you were that worried, why didn't you followed me?
SMG4: I...thought you left to, get something...I didn't know you were upset.
SMG3: Because you never cared.
SMG4: What?

SMG3 turned his face away from 4 and frowned. SMG4 stayed silent just staring at 3 with a small shock.

SMG3: Look, you heard what I said, I'm not looking for any arguments so..let's just forg-

Suddenly SMG4 blocked both sides of SMG3 by pinning him to the wall, he looked angry at him.

SMG4: I always cared of everyone including you! If I wouldn't care i'd let you down back there and take the precious USB with the video! What are you even talking about?!
SMG3: You'd let me down if I wouldn't accept the fact we're friends moron!
SMG4: I.. *sigh* 3, at least accept that you matter to me too.

SMG3 pinned him away from the way and left to back to the room where were their friends. 4 turned around and deeply sighed.

SMG4: Why can't he understand how it really feels. Oh 3..

He slowly slides down on the floor and sat on the floor feeling way worse than before.