The action takes place in Naples in the rich house of the fifty-two-year-old Don Domenico Soriano, a successful entrepreneur. In the room are himself Don Domenico, Donna Filumena Marturano, the woman with whom he lived for the last twenty years, Donna Rosalia Solimene, a seventy-five year old woman who shared the most grievous moments in the life of Filumen, as well as Alfredo Amoroso, an elderly servant of Don Domenico. Once Don Domenico took Philumene to himself from the lowest strata of Neapolitan society; at that time she worked in a house of tolerance. After the death of his wife, after two years of their acquaintance, Filumena hoped that Don Domenico would marry her, but this did not happen. So she lived in his house with Rosalie Solimene in the role of half-slave half-slave, and also
Finally, Filumen decided to put an end to her powerless position: she pretended to be terribly ill, that she was dying in agony, called the priest for the last communion, and then asked Don Domenico to fulfill the desire of the dying and allow her on her deathbed to be associated with him marriage. As soon as Don Domenico complied with her request, Filumena immediately jumped out of bed in good health and told him that now they are husband and wife. Don Domenico realized that he fell for her bait and is completely in her power. Now he is furious and promises that he will spare no money or energy to destroy and crush the insidious.
During an angry bickering, Filumena accuses Domenico that he always treated her low, and even when he thought that she was dying at her bed, kissing a girl who was brought into the house in the guise of a nurse. At the end of her accusatory speech, Filumena claims that she has three sons, whom Domenico does not know about, and that, to raise them, she often steals money from him, and now will achieve the fact that they will also wear the name Soriano. Domenico and Alfredo are stunned. Rosalia has long been aware of this. Filumena asks Domenico not to be very frightened, because the children are not his and already adults. She often sees them, but her sons do not know that she is their mother. One of them with her help became a plumber, he has his own workshop, he is married and has four children. The second one, his name is Riccardo, holds a men’s lingerie store; third, Umberto,
Alfredo confusedly reports that the waiters came from the restaurant And brought dinner, which was ordered by Domenico in the morning, thought that by the evening he would already be a widower and be able to have fun with a young Diana, just the one with whom kissed at the bed of the “dying” Filumen. Soon, Diana herself appears. She is timidly elegant and looks down at everyone. At first she does not notice Philumen, talks about her plans, but when she sees her, gets up and backs away, Filumena treats her quite sharply and turns him out. Domenico swears that, while he is alive, the feet of Filomena’s sons will not be in his house, but she is sure that he did it in vain, for he knows he can not keep his word; someday, if he does not want to die damned, he will have to beg, she’s alms. Domenico does not believe her and still threatens to deal with her.
The next day Alfredo, who spent the whole night sitting next to Don Domenico at the parapet of the monument to Caracciolo, coughs and asks Lucinda to bring him coffee. While he waits, Rosalie comes out of Filumen’s room. She must send three letters on behalf of her mistress. Alfredo tries to find out to whom they are addressed, but Rosalia strictly keeps the confidential secret. Returning from the street, Don Domenico himself drinks Alfredo’s coffee to the great displeasure of his servant. Soon Philumene comes out of the bedroom and orders to prepare two rooms for his two bachelor sons. The married one is left to live where he lived before. Lucia has to move to the kitchen with all her things.
While women are busy with preparations, Diane and Nocella’s lawyer come into the house. They want to talk with Don Domenico, and all three of them are removed to the host’s office. Meanwhile, Umberto, one of the sons of Philumene, enters the dining room, and writes something. Appearing behind him, Riccardo does not pay him the slightest attention and immediately begins to flirt with Lucia. The last to enter is Michele, the third son. Ricardo behaves quite provocatively; his manner of holding leads to the fact that Michele is forced to fight with him. Umberto tries to separate them. Behind this scuffle Filumena finds them. She wants to talk to them seriously, but this is hampered by the invasion of happy Domenico, Diana and a lawyer. Nocella’s lawyer explains to Filumen that her deed was illegal and that she does not have any rights to Don Domenico. Filumena believes the words of the lawyer, but he calls three young people from the terrace, tells them about his life and admits that he is their mother. All three are very excited. Michele is glad that his children had a grandmother, whom they had been asking for so long. Once Filumen is going to leave the house of Don Domenico, he suggests that she move to him. She agrees, but asks her sons to wait for her downstairs.
Left alone with Domenico, she tells him that one of these young people is his son. To say which, she refuses. He does not believe her, being convinced that if she ever waited for a child from him, then she would have used it to marry him. Filumena also responds that if he knew about the alleged child, he would have made him kill. Now if his son is alive, it’s only her credit. Finally, she warns Domenico that if the children find out that he is the father of one of them, then he will kill him. Ten months after the previous events, Don Domenico, who managed to divorce Filomena, is now really going to marry her. During this time he has changed a lot. There are no more imperious intonations, no gestures. He became soft, almost submissive.
In the room there are three sons of Filumen, who came to her wedding. While there is no mother, Domenico talks to them, trying to determine from their behavior and habits which of them is his son. However, it is difficult to make a choice, because all like him, like him, like girls, but none of them can sing, although Domenico himself In his youth, when he was going with friends, he loved to sing, then serenades were in fashion, Philumena comes out of his room ; she is in a wedding dress, very nice and looks younger. Domenico asks young people, along with Rosalia, to go into the dining room and have a drink, and he himself renews the conversation with the bride on the topic that has long been tormenting him: he is interested in which of the three is his son. He asks for her “alms”, which was predicted by Filumen.
All these ten months he came to her house in Michele, and tried to talk to her, but he was always told that Filumenov was not at home until, finally, he came and offered her to marry him, because he understood that he loves her and can not live without her. Now, before the wedding, he wants to know the truth. Filumena is satisfied with Domenico’s test: first she confesses that his son is Michele, a plumber. Domenico immediately tries to come up with something that could improve his son’s life.
Then she assures him that his son Riccardo, and then admits that – Umberto, but the truth does not say. She proved to him that if Domenico finds out who his real son is, then he will sing it out and love more, and the rest will suffer or even kill each other. Their family was too late to become full, and now it must be valued and cherished. Domenico agrees with Filumen and recognizes that children are children, whoever they are, this is a great happiness; let everything remain as before and everyone will go their own way. After the marriage ceremony, Domenico promises young people that he will love them equally, and shines with happiness, when all three, saying goodbye, call him dad.