Sandy, Seth and Ryan travel to Miami, Florida, to visit Sandy's mother, the Nana, after she tells Sandy she is getting married to a younger man. Back in Newport, Kirsten, unable go to Miami with Sandy because of work, is left on her own to deal with her feelings for Carter. Trey misinterprets Marissa's friendship as a sexual advance. Also, Zach invites Summer to a home-cooked dinner at his house.