Rachel Merrell goes into shock when her ex-boyfriend, Jeffery Williams, begins dating her half sister Marlene Draper. At first, Rachel swears Jeff is feigning interest in Marlene just to get back at her for breaking up with him. Rachel pretends Jeff’s interest in Marlene doesn't bother her, but when they unexpectedly hit it off and love begins to blossom, Rachel can't bear to watch the happy couple. Suddenly, Rachel wants Jeff back and she is determined to get him no matter what the cost—including Marlene's happiness.

But when her attempts to regain Jeff's affections fail, Rachel decides to join an online dating service, creating a profile under an assumed name, just to test the waters. Surprisingly, Rachel's profile matches someone who sounds like he'd be the perfect replacement for Jeff, but when she sees a picture of the man of her dreams, she's dumbfounded and pissed: it IS Jeff! Despite Rachel's jealousy over her sister's relationship, she has to tell Marlene the truth about the two-timing Casanova. Now the women will work together to devise a way to make him pay for what he's done...and discover a thing or two about sisterhood in the process.