Source
(Chandler’s cell phone rings. He looks at it.)
Chandler: It’s Joey. (He answers it, holding it out so that Monica can hear too.) Hey Joe.
Joey: Dude, come home!
Chandler: What? Why?
Joey: COME … HOME.
Chandler: Look I, I can’t. What’s going on?
Joey: I don’t know how to tell you this but, uh … I think Monica’s cheatin’ on ya. I told you shouldn’t have married someone so much hotter than you.
(Chandler and Monica look at each other. Chandler nods.)
Joey: All right look. (He walks to the hallway.) If you can’t come home and deal with this, then I’m gonna.
Chandler: NO!
Joey: (outside the apartment door) I just heard him!
Chandler: (softly) Can you … hear him … now?
Joey: (listens at the door.) No. (pause) All right, I’m going in.
Chandler: No! Wait!
Joey: I heard him again!
Chandler: (writhes as if in agony) All right, look. Just stay there. I’m coming home.
I thought it was great how Joey was looking out for Chandler whilst he was away, although he should have known Monica wouldn't have cheated on him.