Friends: Season 5, Episode 10

5 - 10: The One With the Inappropriate Sister

Rachel begins dating Danny. She gets suspicious when he is seen with a mystery women on the subway. It turns out to be his sister Krista. But Rachel and the gang are disturbed by how intimate and childish Danny and Krista are with each other. Meanwhile, Ross is bored whilst on sabbatical from work and drives Joey crazy by re-arranging the apartment. Ross makes it his own mission to teach Joey how to write a script when he loses another acting gig. Chandler's idea of a self-invented game distracts Joey from Ross's coaching, which results in Chandler and Ross becoming rivals.