Following Bobbie's advice to get an assistant, Joey winds up with Glen, who couldn't be better. But when Glen starts dating Gina, his worlds colliding means problems for Joey. Eventually, Gina and Joey create some guidelines so that Glen can continue working for both of them. Meanwhile, Alex mediates Michael's dispute over a patent with his friend Seth.

Joey and Gina's sister Mary Theresa is coming for a visit, and Gina can't stand her because she thinks the world revolves around her. When Mary Theresa discovers that her engagement ring is fake, she decides to call off the wedding and stay in California, leaving Joey and Gina to try to find a way to get her to return to New York. Meanwhile, Michael is oblivious of a girl's interest in him.

As Eric moves out of their apartment and into one across the courtyard, Alex plants herself up in Joey's room with a pair of binoculars as Eric invites another woman over. After Alex goes to bed, Joey sees Eric kissing the other woman. Meanwhile, Joey's got problems of his own: even though he and Sara are allowed to see other people, he's not because he's too crazy about Sara. Trying to make her jealous, Joey discovers that she likes him as much as he likes her, and they decide not to see other people.