From the Valentine's Day episode, 2x14 "Jimmy's Fake Girlfriend"
Jimmy's spirits are low when Sabrina's relationship with Wyatt becomes serious, so Virginia and Burt convince him to create a make-believe girlfriend to make her jealous. Barney invites Jimmy to his improv class, where he meets Mary-Louise (guest star Ashley Tisdale) who agrees to play along with his plan to win over Sabrina. But when their acting becomes too convincing and Sabrina falls for their fake relationship, all plans might backfire on Jimmy. Cast: Lucas Neff as Jimmy; Martha Plimpton as Virginia; Garret Dillahunt as Burt; Shannon Woodward as Sabrina; Cloris Leachman as Maw Maw; Baylie Cregut as Hope; Rylie Cregut as Hope; Gregg Binkley as Barney; Ashley Tisdale as Mary-Louise/Improv Maw Maw
Shannon Woodward & Lucas Neff tease episode 2x14 "Jimmy's Fake Girlfriend"