No dejes la puerta abierta

[The following plot summary is based on the English-language version of this film, Pleasure Cruise ; character names refer to that version.] After he loses his fortune, English gentleman Andrew Poole is delighted to discover that his fiancée Shirley still wishes to marry him. Shirley works in an office, while Andrew tends the house and writes a novel. By their first wedding anniversary, Andrew has become consumed with jealousy over the men Shirley meets at work. Fed up with Andrew's incessant nagging, Shirley decides that she needs a "marriage holiday" and books passage for herself on the ocean liner Nebula . Andrew says that he is going fishing but instead gets a job in the Nebula 's barber shop. He spies on Shirley as she makes friends with other passengers and scares off one of her potential suitors, Murchison, by intimating that Shirley and her husband, who is secretly on the boat, run a scam to blackmail her admirers. Andrew then frightens off another male passenger, Rollins, by telling him that Shirley's jealous husband killed the last man he caught in her boudoir. Meanwhile, Mrs. Signus, a flirtatious older woman, develops a liking for Andrew, whom she mistakenly thinks is a prince in hiding. One morning, Andrew is spying on Shirley from Mrs. Signus' cabin when Mrs. Signus suddenly appears and catches him. She then hides him in the closet when Shirley arrives for a chat. Shirley confides that her husband is the only man who has ever kissed her and that she would like to have more experience. Andrew sneezes in the closet, and Shirley assumes that the hidden man is Mrs. Signus' lover. She thanks Mrs. Signus for her example and prepares to attend a gala costume ball that evening. Shirley is accompanied by English playboy Richard Taversham, who is dressed as "Romeo." Andrew, disguised as "Neptune," overhears as Richard romances Shirley and begs her to leave her cabin door open that night so that he may visit her. While Richard is in his cabin preparing for the tryst, Andrew steals some of his "Stolen Love" cologne, then ties his cabin door shut. Meanwhile, Shirley has become tipsy on the champagne sent by Richard and imagines that Andrew's photograph indicates for her to lock her door. Deciding to be faithful, Shirley locks the door but does not notice as the bolt does not catch. Andrew enters after Shirley has turned out the lights and makes love to her without saying a word. When he leaves, he takes the monogrammed cigarette case that he gave to her before they were married. The next morning, Richard apologizes to Shirley for not coming to her cabin, and Shirley realizes in horror that she does not know the identity of her lover. She disembarks early and goes home, where her friend, Judy Mills, advises her not to tell Andrew of her "infidelity." Just then, Richard arrives and Shirley is confused by his claim that the barber shop attendant gave him her address and said that she wanted him to visit her. Andrew arrives home a short time later, and Richard is shocked to recognize him as the attendant. As Andrew escorts Richard to the door, he shows him the cigarette case, and the relieved Richard nods that he understands Andrew's subterfuge. Shirley sees the interchange in a mirror and figures out the deception her husband has practiced. She confesses that she spent the night with another man, but states that she is not ashamed, for she is proud to have appealed to "such a lover." Shirley then tells Andrew that her lover is in the bedroom, and as he looks at himself in the mirror, she informs him that she knew all along that he was on the boat. She then tells him to knock the next time he wants to make love to a lady, and closes the bedroom door. Andrew smiles and knocks, then goes into the bedroom.