Summer House takes the beach town of Montauk, New York by storm, while following a group of nine friends who make the exclusive enclave their go-to party spot between Memorial Day and Labor Day — that is, when they're not hustling at their day jobs. You could say they work hard and party way harder.
With the summer house finally back to its free-spirited, hard partying ways, Amanda begins to show her frustration with Kyle’s continued boozy behavior and decides to let him have a weekend to himself. Lindsay gets in touch with her ex, Everett after failing to forget about him. Meanwhile, Lauren and Carl appear to have moved past the fiasco from the 4th and are back to being friends (with benefits) but Danielle continues to be an unwelcome third party in their relationship.
Before Carl and Stephen resolve the bomb that fractured their friendship in the city, the gang hosts several housemates' moms for the weekend in the Hamptons. Despite everyone being on their best behavior, things soon go off the rails when Lauren calls Carl out on his dishonesty. Lindsay tries to be a good friend and play peacemaker while Kyle braces for his mother officially meeting Amanda’s mother and gets nervous about this step being bigger than he anticipated.
Kyle and Amanda attempt to repair their ever-growing rift; Carl chooses to put his cards on the table with his latest lady friend; Lindsay has some shocking news for Everett; Lauren's twin, Ashley, returns and sees some welcome changes in her sister.
The housemates return to the Hamptons with several new friends in tow; unresolved issues between Kyle, Lindsay and Danielle quickly spread through the house; Carl vows to focus on his work and never hook up with a summer share housemate again.
Lindsay confronts Kyle about the shocking rumor and he subsequently tells Amanda the real story. Meanwhile, Carl's mom comes to town to surprise him. The housemates continue to wonder about what secret Jordan may be hiding. After Amanda ignores Kyle all week, he desperately waits outside of her office to confront her.
Jordan finally meets a woman he'd bring home to mother; Kyle's L.A. buddies, Stassi, Beau, Katie, and Tom, pay a visit; Stassi tries to help Lindsay see she deserves better from men; Carl and Paige argue over who misled whom.
The Vanderpumps continue their visit; Kyle accuses Paige of leading Carl on; Hannah tears into Jordan; Carl brings a date to the house; Tom has an emergency requiring a trip to the hospital; Kyle reveals he's ready to propose to Amanda.