Stan visits Atlantic City for his "best friends" bachelor party, only to find out he was accidentally invited. Roger steps in and becomes Stan's new best friend. They get drunk one night, and engage in some sort of alien friendship ceremony, which takes their friendship to a whole new level. But when they return home, they realize that what happened in Atlantic City didn't stay there. Meanwhile, Steve and Hayley team up to break up a couple so they can reap the benefits.