3x23 "The One with Ross's Thing"

Afflicted with a mysterious skin condition on his behind, Ross seeks advice from Phoebe's herbalist (Kevin McDonald). Phoebe can't choose between dating a fireman or a Kindergarten teacher and attempts to date both behind each other's back. Monica can't decide what to do about Pete when she thinks he is going to break up with her because Pete says when he gets back from Atlanta, They need to have a talk, So she's having a hard time deciding on what's he is going to do.