Shannon and David are pushed to new limits as they finish up the last day of their couples retreat.  Meanwhile, having returned from Puerto Vallarta, Vicki throws a Fiesta party where a piñata isn't the only thing that's bashed. At the party, when Heather introduces her friend Meghan to the group, Shannon realizes that she has a history with Meghan. Plus, Vicki and Tamra's shaky friendship becomes even more complicated as the two come face-to-face after having avoided each other for the past six months.