Childhood friends Julianne Potter (Julia Roberts) and Michael O'Neal (Dermot Mulroney) had a deal to marry each other if they were still single by age 28. Now, four days before her 28th birthday, O'Neil announces that he's marrying a gorgeous 20-year-old named Kimberly (Cameron Diaz). Suddenly realizing that she's actually in love with him, Julianne vows to stop the wedding at... Wikipedia