We meet the three characters of Ménage just as they apparently meet each other in a dinner club. Antoine (Michel Blanc) and Monique (Miou-Miou) are having a huge fight at their table, when up walks Bob (Gérard Depardieu), who gives Monique a full-on blindsiding slap to the face to make her shut up. At first you wonder: Is Monique a prostitute? Do these two know Bob? How are any of these people related? Turns out, that is the first time Antoine and Monique (who are actually a married couple) meet the mysterious Bob. Bob, because he is played by Gérard Depardieu, is apparently a very seductive and sexy con artist (oh, how the French love him!), and he is also bisexual--which is meant to be obvious because he is wearing black leather pants (you see?).
Since Antoine and Monique are basically living in poverty and Bob has enough money to wear leather pants, it only takes a fur coat here and a nice suit there to convince them to jump on Bob's bandwagon and leave their decrepit trailer in flames (Bob has his ways). Turns out Bob is a flagrant thief, walking right into rich people's mansions, making himself at home, eating their food, sleeping in fine beds, and taking what he wants.
Bob also very boldly wants Antoine, even though Antoine is straight and devoted to his wife. Monique finds this all a hoot, and thinks it would be grand idea for Antoine to just relax and get, well, "butt-f**ked". This discussion comes up A LOT until Antoine abruptly seemingly falls in love with the wily Bob and becomes his bitch. Um. What?
Ménage unfortunately coasts by the "a trois" part of the equation, even though Monique seduces the very reluctant and uninterested Bob in one scene. Once the two men are together and the three of them set up house, Monique is treated like a maid, not invited to their bed, and Antoine is stuck playing bitter housewife while Bob goes out cavorting. This second half of the film is strange and grim after the somewhat jovial romp of the first act. When it culminates with a desperate Antoine going out with Bob in full drag just to get out of the house for a change, the character arcs have become so unbelievable that you can only throw up your hands.
This film was made in 1986 and perpetuates flamboyant gay stereotypes despite the refreshing sexual fluidity of the characters. Apparently Ménage can be seen as a companion piece to the film Les Valseuses (which I haven't seen) that also starred Depardieu and Miou-Miou. But that fact is probably the only curiosity factor that would make this disjointed film worth seeking out.