Tom Sandoval throws a competing pool party on the same day as Jax, forcing everyone to choose sides once and for all. Brittany blames Katie for the rift in their friendship, while Max and Brett nearly come to blows over their feelings for Dayna. Schwartz and Sandoval must decide whether to double down on their investment with Lisa, James makes a surprising ally, and Ariana erupts when Kristen tells her that Stassi has been making fun of her house.