Quote from Phoebe in The One with the Ring
Phoebe: Have you told anyone else? Chandler: No, I haven't told anyone else because I don't want Monica to find out. Phoebe: You told me. Chandler: Well, that's because I trust you, and we're friends, and you walked in on me while I was looking at ring brochures. Phoebe: Yeah, well, once again, not knocking pays off. I only wish you hadn't been on the toilet. Chandler: Me too.