Nina (1959)
Directed by Jean Boyer

Film Synopsis

Adolphe Tessier, a modest clerk, is shocked to discover that his wife Nina has taken a lover.  Worse, the man in question - a rich idler named Gérard Blonville - is a compulsive philanderer for whom Nina is seemingly just a passing infatuation.  Adolphe may not be particularly enamoured of Nina himself - she is bossy, talkative and clinging to a fault - but he still feels he has to defend her honour.  He confronts the loathsome Gérard with the intention of inflicting upon him a scoundrel's retribution, but he has a change of heart and instead they become firm friends. Adolphe and Gérard are two men united by a common enemy: Nina. 

Of course, Nina feels very differently about the matter.  By now, she realises that she cannot exist without either man.  Both are essential to her future happiness, so she must somehow find a way to get them to live with her under the same roof.  This she does by feigning illness.  For both men, this is the final straw and they agree to get rid off the troublesome minx once and for all.  After an attempt to poison his unwanted mistress fails, Gérard decides to slip away quietly to Mexico but he injures himself when he falls down the stairs.  In the end, Nina obtains what she has always wanted - herself, her husband and her lover, all together in the same bed...