6x02 "The One Where Ross Hugs Rachel"

Monica and Chandler tell Rachel and Joey that they're moving in together. Joey takes the news badly, and Chandler reassures him that their friendship won't be affected. On the other hand, Rachel takes the news surprisingly well, but only because she doesn't realize that if Chandler is moving in, she will have to move out. Eventually when Monica explains the situation, Rachel is distraught and seeks comfort from Ross. Phoebe thinks Ross still loves Rachel because he didn't get the annulment, and her belief is strengthened when Ross hugs Rachel in an attempt to comfort her and smells Rachel's hair.