Monica: (still thinking it's Phoebe who's pregnant) Wow... Between me and you?
Rachel: Yeah...?
Monica: In this day and age, how dumb do you have to be to get pregnant?
Rachel: (offended) Hey! Y'know... sometimes you can do everything right... everyone can wear everything they're supposed to wear... and one of those little guys just gets through!
Monica: How?
Rachel: I don't know... maybe they have tools.