Carrie is invited to go up to their Hamptons beach house by Patience and Peter, but in the morning she bumps into Peter in the hall without his underwear on. Some friends introduce her to Sean, 'The Marrying Guy'; when she can't keep up on his quick-march to commitment, he ditches her for commitment-phile Charlotte. Miranda's colleague from work, Jeff, introduces her to a lesbian, Sid, at a baseball game, and they are invited to her senior partner's dinner party.

Charlotte is dating Jack, who wants a threesome, but she is unsure. Carrie discovers that Mr. Big has an ex-wife, and feels threatened. Samantha is seeing a married man; when his wife finds out, she proposes a threesome to keep their marriage together. Miranda feels unattractive and looks for affirmation that she isn't.

Carrie's smoking becomes a problem when she goes on her first date with Aidan Shaw. Miranda makes more time for Steve in her life. Charlotte dates the worst kisser she's ever met. Samantha dates a black man whose sister is racist.