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.