Paul Bongard (Peter Kastner), a college graduate in his mid-twenties who is part of the "now" generation more by default than choice, directs television commercials for a Madison Avenue advertising firm.

Returning from a San Francisco business trip to New York, he sits next to ultra-attractive 18-year-old Marilyn Monroe (Joanna Cameron). As Paul talks with Marilyn during the flight, his manner changes from flippant to super-charming, only to have Marilyn blurt out that if he is interested in having sex right there on the plane, she is agreeable.

Meanwhile, Paul has visions of disloyalty to his steady girlfriend, Ruth (Louise Sorel), whom he first romanced when they were growing up in suburban Connecticut. As Paul and Marilyn become more passionate in their lovemaking, so do the parallel love memories of his evenings with Ruth when he tried to seduce her.

Back in New York, Paul jaunts into the Parks Advertising Agency, only to learn that he as been demoted in his job - he has been relegated to an office in the hall. Paul confronts Finley Harris (Richard Schull), his superior, for the reason and learns that the client was dissatisfied with the commercial Paul directed in San Francisco. Harris suggests that Paul resign but he refuses, knowing the agency will not fire him due to potential bad publicity.

The next noon, Paul has lunch at P.J. Clarke's Bar with Ted Busman (Gary Burghoff), a pal and fellow worker in the advertising media. Paul expresses his confusion over his career and his indecision about marrying Ruth.

That evening, Paul encounters Marilyn at a midtown bar, and they heatedly begin to relive their exotic plane trip. Marilyn is most anxious to continue the romance right on the dance floor, asking Paul to talk dirty to her, but he panics and leaves the scene. He walks the streets, agitated by the passing events of his present and past life.

The next day at work, Harris tells Paul that if he will take the blame for an overbudgeting error in a client's account, he will help get him a new job with Ink, Dreyfus and Zimmerman, a top-notch advertising agency. Paul reluctantly agrees.

Later, Paul returns to his apartment, but gets the feeling that someone has broken in. He finds Marilyn waiting for him on his bed in a bikini. Still rattled by her conduct at the night club, Paul tries to discourage Marilyn from pursing him, but she ignores his rebuff and instead turns on the record player, performing a seductive striptease. Paul succumbs and they resume their affair.

When they finish having sex, Marilyn comments on how "good" Paul was and he seems remorseful. Paul doesn't understand why sex always has to be "dirty" with Marilyn and tells her a little love would be nice. Taken aback, Marilyn angrily informs him that what they did was just sex, and that love didn't have anything to do with it. She soon switches back into her happy, carefree mood, confusing Paul further.

Arriving at his new job, Paul is confronted by attractive Jane Ink (Joanna Barnes), who is in her late thirties, cool, ambitious and aloof. Jane makes it quite clear that she knows how Paul got his new position and that he better tow her mark if he wishes to succeed. Paul understands and accepts.

Paul soon begins his filmmaking with great joy, despite the depressing unreality of his profession. Jane suggests Paul spend evenings working with her at her apartment and he agrees. At her apartment, Jane coquettishly romances Paul, and he, being more bewildered than experienced, accedes to her advances. Jane suggests Paul accompany her on business to Hollywood.

Paul finds himself more comfortable in his new job with Jane, and is able to relax more in the love-play she demands.

Back in New York, Paul meets Ted in the steam room of a health club to discuss the progress of his job and love life. Under Ted's close scrutiny and questioning, Paul's overall confusion becomes more apparent.

Returning to his apartment, Paul finds Ruth there, wanting to know where their emotional life together is heading. The next day in Central Park, they continue their discussion with the problem of the Jane Ink relationship crowding into their talk. At the agency, Paul screens for Ruth a new film he has made and she finds its distasteful. Jane comes into the room and informs Paul that he will need to meet her at the apartment to go over the script that night, even though he had planned to spend the evening with his college sweetheart. Losing his nerve, he caves in and agrees to be there. Ruth can easily see that Paul is not only sleeping with his boss, but is also afraid of her. Angry and hurt, she leaves for Connecticut.

Later Jane admits her embarrassment about the situation and introduces Paul to her daughter, Michele, who turns out to be Marilyn! The shock causes him to pass out.

Michele still desires Paul, and he is caught in a bind. When Jane finds out that he has also been romancing his daughter, she returns to Los Angeles on business, taking Michele with her and forcing Paul to stay behind. Walking the streets once again, Paul takes a long hard look at himself. As Ruth said, "it's time to grow up". Paul sees his reflection in a shop window and realises that maybe his job isn't worth giving up Ruth for. On the coast, Jane calls Paul to tell him that he isn't fired and that she still needs his artistic abilities, but on her terms. Finally standing up for himself, he tells her to "shove it" and bolts out the door, determined to re-establish his relationship with Ruth.

Paul calls Ruth to tell her the wonderful news, but she informs him that it's too late, she's about to get married to someone else. Paul rents a car and drives frantically to Connecticut to try to change her mid, only to learn that Ruth and her groom-to-be have left for New York and their honeymoon boat trip.

Paul rushes back to the city and to the dock, where he finds Ruth, standing alone. They depart together.