(Chandler, Monica, Phoebe and Joey are leaving…)

Rachel Green (to Joey): Hit the lights, please.

(Ross comes out of the restroom to a dark room)

Ross Geller: How long was I in there?

Rachel Green: I’m just cleaning up.

Ross Geller: Oh, you need any help?

Rachel Green: Okay, sure. Thanks.

From Friends – Season 1 Episode 2: ‘The One with the Sonogram at the End’ (1×02)