Rachel: Ross, you had sex with another woman!
[ Cut to Monica’s bedroom, both Monica and Phoebe gasp. ]
Phoebe: Oh, I knew something had to be wrong, because my fingernails did not grow at all yesterday.
Chandler: Yeah, well, I guess they had a fight, and he got drunk…
Monica: Oh!! [hits Chandler and Joey on the head] You guys knew about this and you didn’t tell us?!
Chandler: [To Joey] He has sex, and we get hit on our heads.