Help finding French movie title?

[Savannah7165]

I'm trying to find a movie where a woman's son runs away and in order to get him back, she calls up some old friends, two gentlemen, and tells them each that they might be the father of her son. She does that so they will want to help her find him. Anyway, the two men set off looking for her son. One of the scenes is one man with big curly hair being forced to eat a hamburger with his tie in the middle of it....

I can't remember the title!!! Does anyone know what it is??