Quincy Watson (JAMIE FOXX) and his cousin Evan Fields (MORRIS CHESTNUT) work together at Spoil Magazine where they have a new boss, Philip Gascon (PETER MacNICOL). When his live-in girlfriend, Helen Sharp (BIANCA LAWSON), unceremoniously dumps him, Quincy quits his job and sets out to write a "how to" manual about ending romantic relationships. It's soon a bestseller and Philip asks for Quincy's help in breaking up with his gold-digger girlfriend, Rita Monroe (JENNIFER ESPOSITO), who does not intend to let her rich catch get away.
Meanwhile, Evan mistakenly begins to believe that his girlfriend, physical therapist Nicky Callas (GABRIELLE UNION), is about to break up with him. Thus, he sends Quincy to a bar to talk him up to her. Yet, since he's never met her and she's changed her looks from the description Evan gave him, Quincy doesn't realize he's talking to her, although she does. Meanwhile, Rita learns that Philip is using Quincy as his coach and decides to exchange sexual favors for him laying off the plan.
Unbeknownst to Quincy, however, Evan decides to pose as him to her. From that point on, Quincy finds himself falling for Nicky all while the resulting mistaken identities cause comedic complications to pile up.