Ça reste entre nous (1998)
Directed by Martin Lamotte

Film Synopsis

Patrick is a happily married man.  The reason for his happiness is that, as well as an adoring wife, Hélène, he also has an equally adoring mistress, Elisabeth.  Naturally, leading a double life of this kind requires some energy and organisational ability, but fortunately Patrick has both of these in abundance.  Hélène is the mother of his two sons, Elisabeth is the mother of his daughter, so Patrick feels it only right that they should each get their fair share of him.  Needless to say, neither woman knows what Patrick is up to.  To them, he is the devoted partner and ideal father.  Of course, it is all too good to last...  On the very day that Hélène has arranged something special for their wedding anniversary Elisabeth wants Patrick to attend a neighbour's engagement party.  There are not many people that can be in two places at the same time, but this is what Patrick must somehow manage if he is to prevent his two-timing chicanery from being discovered...