The One With Ross's Library Book

Rachel and Phoebe convince Joey to keep dating a girl that they like. However, the girls must decide whether to tell Joey when they find out that she's not interested in a serious relationship with him. Monica unintentionally invites Janice to her wedding. Ross is proud to find his thesis in the library but gets upset when he discovers it is in a section that is so deserted that students go there to make out.