Quote from Ross in The One with Ross's Sandwich
Rachel: What is the truth? Ross: Yeah. What's up? Phoebe: What's going on? Joey: I slept with Monica. Chandler: Well, let's see what everybody thinks of that. Monica: Oh, no. Ross: You slept with my sister? Joey: Yes, but it was- We just did it once, in London. Ross: This is not good for my rage. [gets his pill bottle out]