Carrie runs into an old friend at her internship and gets invited to his mother's dinner soiree in Manhattan, but her feelings for Sebastian get in her way, until she see him with another girl. Mouse is excited about getting back together with Seth, but her worries about being bad at sex drive her to ask Walt for help. In order to hang on to a favorite spot at the diner, Maggie takes on Donna LaDonna and her friends. Meanwhile, Tom loses his wedding ring, which makes him realize that Harlan might be right about starting to date again.