Marcus asks Will for advice on how to get invited to a girl's birthday party.

Fiona oversees a project for Marcus' class. Later, Marcus goes on a shopping spree with Will.

Looking to make some quick cash, Will decides to start teaching guitar lessons. However, after a fling with his student's mom, Emma, Andy speculates that Will is being paid for more than just his musical expertise. Elsewhere, Fiona finds herself suddenly accepted by the popular moms at school and Marcus prepares to perform at the upcoming school fundraiser.