Matt Sullivan (Josh Hartnett) and his roommate, Ryan (Paulo Costanzo), are co-workers at a San Francisco, California dot-com company. Matt is obsessed with his ex-girlfriend, Nicole (Vinessa Shaw), and his obsession repeatedly causes him problems during attempted one-night stands. He has trouble moving on, since Nicole broke up with him. He confides his sexual problems to his brother, John (Adam Trese), who is training to become a Catholic priest. In an attempt to fix his problems, Matt vows to chastity, including masturbation, for the 40 days and 40 nights of Lent. John warns Matt that chastity is not easy; meanwhile, Ryan starts a popular office pool to bet on how long Matt can last.