Mr. Big and Carrie buy a magnificent penthouse in Manhattan and they decide to get married. Enid Frick invites Carrie to take pictures for a special edition of Vogue about marriage of women of forty and something years. During the preparation, Carrie raises the guest list from seventy-five to two hundred guests, and a simple wedding dress to a fashionable Vivienne Westwood, intimidating Mr. Big in his third wedding. Meanwhile Miranda has no sex with Steve and he confesses that he had had one night stand with a woman. On the eve of the wedding, in the rehearsal dinner, the upset Miranda tells Mr. Big that marriage ruins everything. On the next day, the scared Mr. Big calls off the wedding leaving Carrie in the church. Carrie feels humiliated and depressed and Samantha, Miranda and Charlotte decide to travel to Mexico with Carrie to the hotel where she was supposed to spend her honeymoon. When Carries returns, she hires the assistant Louise to help her to organize her life. When Miranda discloses what she told to Mr. Big to Carrie in the rehearsal dinner, their friendship is shaken.