Giorgio, married to Daniela, would like to take his beautiful lover Gloria somewhere to spend the night. So he asks his brother-in-law Marco, who is leaving for a week in New York with his wife Lucia, to lend him the house. Although Marco is a little hesitant, he eventually agrees. After a romantic dinner, Giorgio goes to Marco's house with Gloria to spend a night of sex. But the couple did not take into account Enzo, the boyfriend of Ilenia, the cleaning lady of that house, who, being up to his neck in debt to a loan shark, had entered the apartment shortly before with the intention of stealing something. Thus begins a long night during which all sorts of things will happen.

Marco sta per partire insieme alla moglie Lucia per una settimana di vacanza a New York. Controvoglia accetta di lasciare le chiavi di casa sua a Giorgio, un caro amico nonché cognato che vuole portare nell'appartamento Gloria, appena conosciuta. L'uomo vorrebbe passare una notte rovente con la ragazza, ma i suoi propositi si scontrano con Enzo, il fidanzato di Helena, la donna delle pulizie che ha urgente bisogno di denaro per sanare i suoi debiti con un usuraio.