1x05 "The One with the East German Laundry Detergent"

Chandler and Phoebe decide to break up with Janice and Tony at the same time, and Phoebe's goes well but Chandler has a harder time requiring Phoebe's help. Ross arranges to do laundry with Monica and Rachel but Monica cancels leaving just the two of them. Rachel reveals she's never done laundry before but Ross helps her stand up to a woman and Ross gets his first kiss with Rachel. Joey wants to go out with his ex-girlfriend (Angela) who now has a boyfriend (Bob), so he arranges for Monica and him to double-date with them by leading Monica to believe that Angela and Bob are siblings and therefore Angela's actual boyfriend is Monica's date. This creates much confusion when Monica sees Angela and her "brother" being 'inappropriate' but it eventually works out for Joey.