In London, insurance executive Steve Blackburn and fashion designer Vickie Allessio meet while mutually hailing a taxi in the rain. Having coincidentally seen Vickie earlier in a park and then on a bus, Steve is attracted to her and delighted to learn that while she has two children, she is divorced. Despite his own marriage and two children, Steve invites Vickie to tea the next day and at that meeting, asks immediately if they can lunch together the following day. Amused, Vickie discerns that the overzealous Steve would like to instigate an affair and, attracted to him as well, agrees. After a hasty lunch the following day, Steve takes Vickie upstairs to a small hotel room where she admits that as a hard-working single mother she is perfectly amenable to an affair with an attractive married man who will not burden her with emotional complications. Nevertheless, because she must return to work and would prefer they not begin in a second-rate hotel, Vickie suggests that Steve arrange a weekend for them somewhere on a beach in the sun. Elated, Steve agrees and hastening back to his office studies a weather chart and settles on sunny Malaga, Spain. Visiting Vickie at her office later that day, Steve proposes they spend a week together and, despite numerous business demands, Vickie agrees to depart with Steve the very next day. Although Steve has several anxious moments arranging his trip when it appears that his wife Gloria, who has returned home unexpectedly early from visiting her parents, will join him with their children on his trip, he at last succeeds in making the clandestine reservations for him and Vickie alone. At the airport the next evening, Steve is dismayed to run into old friend Walter Menkes, a jovial film producer thrilled to find a flying companion, thus forcing Vicki to sit apart from Steve. Upon arriving in Spain, Steve’s plan to rent an elegant roomy car ends when it proves to be the last car available and, to avoid sharing with Walter, Steve allows his friend to have it. Hoping to be rid of Walter, Steve agrees to dine with him the following night and is finally able to depart with the increasingly fatigued Vickie in a tiny Italian model car with an uncertain clutch. After an initial mix-up over rooms at the hotel, Steve and Vickie finally settle into a double room up three flights with a view overlooking Gibraltar. As the couple settles into bed, Vickie comments how nice their view is and, turning abruptly to look, Steve throws out his back. By the time the manager brings a doctor to tend to Steve, Vickie is exhausted and falls asleep. The next morning, Vickie leaves the sleeping Steve and visits the street markets where she meets an American woman so pleased to meet another English speaker, that she invites Vickie to dinner that evening. Awakening later to spot Vickie on the balcony in a bikini, Steve is aroused and, with his back now mended, he and Vickie finally have sex. Afterward, Vickie is eager for lunch, but Steve insists on knowing how she felt about his sexual prowess. Crushed when she describes the experience as “very nice,” Steve complains bitterly, until an exasperated Vickie pronounces him a “typical American male,” which only infuriates Steve further. Despite the argument, Steve grudgingly allows Vickie to accompany him golfing where he soon starts a competition with his young caddy, Enrique. When Steve’s game falters, Enrique’s family and friends join the betting pool against him, but are disappointed when Steve ultimately wins. Certain that Steve initially played poorly intentionally, Vickie storms away in a huff and does not see Steve refuse Enrique’s money. Still annoyed with Vickie, Steve announces that he is dining out that evening. Meeting Walter later, Steve is chagrined to find Vickie at the table, as Walter’s wife Patty invited her at the street market. Irritated by Walter and Vickie’s discussion of Gloria and their children, Steve fumes back at the hotel room and another argument breaks out when Vickie mocks his oversensitivity. Agreeing that the trip was a mistake, Steve and Vickie decide to return to London immediately, but Steve refuses to contact the airlines and only upon arriving at the airport do they learn that the only London flight is sold out. Angrily returning to the hotel, the couple has a huge fight until, realizing their own foolishness, they burst into laughter and fall into bed together. Over the next few days, Steve and Vickie enjoy a romantic idyll as the Menkes watch suspiciously from a distance. The day before returning to London, Steve is taken aside by Walter who warns him not to fall in love with his mistress as it will be costly to them both. When Steve relates the advice to Vickie, she agrees but Steve insists he will not give her up. On their return to London, the couple rent and renovate a run-down Soho neighborhood flat in a building frequented by prostitutes and over the next several months continue their romance. Although it is initially lively and fun for both, Steve finds himself increasingly with conflicting family and work obligations that force him to miss repeated dates with Vickie. Undaunted, Steve slips away to visit Vickie at any opportunity, including while ostensibly walking the dog or during the intermission of a symphony concert. Although Vickie makes no complaint, Steve becomes aware of her growing disappointment and turns to Walter for advice on how to break with her. Steve arranges to meet Vickie for a serious talk, but rather than ending the relationship, he confesses that he loves her and cannot do without her. Soon after, Steve’s work again interferes with a planned date with Vickie which they rearrange for later that night. Telephoning Gloria to say he will be late, she reminds him of a charity concert they must attend that same night and he hurries home to change. Later, Vickie visits a nearby market to get spices for the dinner she is preparing for Steve and happens to see Steve and Gloria exiting the theater across the way. When Steve arrives later and lies about having been at work, Vickie informs him that she saw him at the theater and begins berating him until she realizes that she sounds like a wife. The next morning at dawn, walking to his office, Steve orders a telegram sent to Vickie gently breaking off their relationship. By the time he has reached home, however, Steve has changed his mind and calls to cancel the telegram. Vickie receives the telegram nevertheless and while listening to a pop song about romantic heartbreak, struggles in vain to come up with a sincere reply. While Steve hurries to buy groceries on his way to the flat, Vickie packs all her clothes and departs. Arriving at the flat, Steve finds his crumpled telegram and, glancing out the window, spots Vickie waiting in the rain for a taxi. Smiling wistfully, Steve turns off the record player.