Pierre Levasseur (Daniel Auteuil), an important CEO, is photographed with his lover, Elena (Alice Taglioni), a world-famous model. In an attempt to salvage his marriage, he tries to convince his wife that Elena is not his lover, but that of François Pignon (Gad Elmaleh), a valet who was passing by and ended up on the photograph. To make his story believable, Levasseur then has to convince Pignon and Elena to move in together and to pretend to be a couple. Things get more complicated when this creates tensions between Pignon and his former flatmate Richard (Dany Boon) and his love interest Émilie (Virginie Ledoyen), and when Levasseur's wife, Christine (Dame Kristin Scott Thomas), discovers the truth, she decides to play games with her husband.—Pruneau