Heartbreaker( French :L'arnacœur) is a 2010 French romantic comedy film starring Romain Duris , Vanessa Paradis , Julie Ferrier and Andrew Lincoln .

The bulk of the story takes place in Monaco . The plot is centered around Alex ( Romain Duris ), his sister ( Julie Ferrier ) and her husband (François Damiens), who operate a business designed to break up relationships, but only where the woman is "not knowingly unhappy." The trio concoct elaborate, custom ruses to deceive the women. After each woman has fallen for his act, Alex tells her she has made him come alive again, but that it is too late for him. The women presumably each leave their relationships to seek men who makes them feel as Alex has.

They are hired by a wealthy man (Jacques Frantz), who is a florist and possible gangster, to prevent the wedding of his daughter Juliette ( Vanessa Paradis ) to Englishman Jonathan ( Andrew Lincoln ). The problem is that they only have 10 days to do so before the wedding. The task is further complicated because the couple appear to be in love and absolutely perfect for each other. They also could not find the usual "flaws" in the couple that they are used to looking for in couples to break them up. Alex, massively in debt to a loan shark through his own lavish spending on the business, is pressured into putting aside his honourable principles to complete the seemingly impossible job with only five days till the wedding.

Alex becomes Juliette's bodyguard in order to gain close and constant access to her. While on the job, Alex finds out things that Juliette likes and pretends to like these things as well to impress her; some of these things includeDirty Dancing, Roquefort cheese and George Michael . Eventually the two develop feelings for each other but the early arrival of Jonathan disrupts Alex's access to Juliette. The night before the wedding Alex and Juliette sneak out and have a wonderful time, and early the next morning Juliette confesses her feelings for him. Alex begins his usual script but, realising he cannot be with her after how he has deceived her, abruptly changes it and says she should get married.

The next day as Alex is leaving the hotel, his brother-in-law inadvertently drops Juliette's case file in front of her. Seeing the surveillance photos and her background information, she realizes her father has hired Alex to try to stop the wedding. Alex leaves for the airport, but his sister chides him for walking away from real love to return to an empty life of fake seduction. He runs toward the wedding from the airport.

Meanwhile, Juliette's father tells her that while Jonathan is a decent man, she will be bored with him. While they are walking down the aisle, he tells her that Alex refused to take any payment for the contract. Before reaching the end of the aisle, Juliette turns and runs away from the ceremony to find him. The two meet and kiss after Alex confesses that he hates Roquefort and George Michael and has never seen Dirty Dancing, but still needs to see her every day.

As the credits roll it is revealed that the loan shark Alex owes money to actually works for Juliette's father.