Phoebe and Ross end up talking about how he has never been in a long term relationship before, and it gets him thinking about what is wrong with him.
Meanwhile, Monica barges in on Chandler being a happy camper and makes a startling discovery once she enters the room.
Joey, on the other hand, tries to remember who this 'girl' really is and when he slept with her... But in the end, he relaizes that it wasn't HER he slept with, but her sister!
This episode was funny, but it wasn't up to the full potential of 'Friends'. I enjoyed it, overall.