Heartbreaker
(2010)

Alex (Romain Duris), his sister and her husband have a business where they are hired out by the families and friends of women who are stuck in unhappy relationships.  Alex pretends to be the women’s perfect man, and helps them to see what a terrible relationship they are in, giving them the strength to walk away.  He is always careful not to take advantage of the women, pretending to have a past that causes him to be unable to fall in love.

Hired by a rich man to stop his daughter Juliette’s (Vanessa Paradis) wedding in 10 days, Alex pretends to be her bodyguard as he cons her into falling for him.  In the end, it is Alex who falls for her, and he must let her go and realize he cannot live a lie as a con man any longer.

It takes until the last moment for Juliette to realize that although her fiancé is perfect, he is not perfect for her and she loves Alex.  When they meet again, he confesses all his lies and tells her he can be himself with her.  Juliette realizes that she can be herself as well and they kiss.

Thanks LiliRoze!