Flash Forward - Season 1 Episode 19 Mud Pack

When Becca discovers the secret location of the ninth graders' annual bash, she spills the top secret information to Kerry, who's incapable of keeping it mum. To salvage her reputation, Becca plans a new bash at her vacationing uncle's empty house. But Ellen also decides to take advantage of the empty house and plans a date with her boyfriend for the same afternoon. Tucker, who's been grounded, sneaks out to warn Becca that her sister is on the way.