My Three Sons - Season 12 (1971)

Fergus (Fred MacMurray in a double role) marries Terri (Anne Francis), a woman who works at a bowling alley. They fly to Las Vegas for their honeymoon, before going home to Scotland.

Everyone has a busy day, and no one has time to take care of the triplets. Steve decides to take care of the boys by taking them to work, and asking his secretary to take the day off to care for them. Steve then forgets where she lives.

Chip asks Polly to stop buying useless things as their apartment does not have enough room. When she goes shopping again, a salesman tells her she can have a free set of cookwares - if she hosts a dinner party for eight people that night.

Charley goes on vacation to San Francisco. Meanwhile, the women of the house all have birthdays in the same week, and their spouses forget the occasion.

Katie (Tina Cole) flies to Peru to spend some time with Robbie (Don Grady). She leaves the triplets with Chip (Stanley Livingston) and Polly (Ronne Troup), who find it difficult to be instant parents.

Babara (Beverly Garland) is enthusiastic about everything that involves Steve (Fred MacMurray) and his family, almost to an embarrassment with Steve. When Steve asks her to join his partners and their wives at a bowling match, she is afraid of letting him down.

Katie (Tina Cole) wants to do more than just stay at home with the triplets, so she gets a job singing in the evenings at a small coffee house. Steve (Fred MacMurray) and Charley (William Demarest) worry about her, but once they meet the owner (Anthony Caruso), they realize Katie is in good hands.

Polly wants to learn more and experience more so that she is more interesting to Chip. Since Ernie sees her going out a lot without Chip, he start to think there is something wrong with their marriage.

Charley is asked to be a substitute teacher in a music class, teaching the students cello for an upcoming musical. The students do not appreciate his method of teaching.

When Katie (Tina Cole) is out with the triplets, a talent scout notices the boys and wants them to be in a television commercial. While filming, the boys act out since they are afraid. Steve ends up in the commercial so the boys feel more comfortable.

Katie (Tina Cole) gets a temporary job as a secretary, and decides to put the boys in a child care center, so that Charley (William Demarest) is not bothered with three young boys. Soon Charley goes missing every day from home at the same time.

Dodie (Dawn Lyn) tries to avoid first grader Alfred (Tiger Williams), who likes her and follows her everywhere.

Katie (Tina Cole) is feeling particularly lonely with the continued absence of Robbie (Don Grady). Steve, Charley and the others each take her out to dinner on different nights to cheer her up.

Dodie's school has a fund raiser to send to Korean orphans. She tells her teacher that her father will help divide the peanuts in a large sack into smaller bags for the sale. The whole family works all night to complete the task.

Ernie's school project is to see how the phases of the moon affect people. He notices that Steve becomes more accident prone.

Barbara (Beverly Garland) wins a cooking contest and becomes one of the finalist. The cook-off is in Hawaii.

Barbara (Beverly Garland) is not feeling well, but finds out she has to take care of the children and the house by herself. When she cannot take it anymore, she walks out the house without telling anyone.

Dodie (Dawn Lyn) is upset when she realizes Tramp disappears every evening. Tramp is getting old, and Dodie is worried he might not find his way home.

Katie (Tina Cole) and her friends talk about their husbands. Katie misses Robbie and wonders if she should start living her own life without him. Meanwhile, Dodie (Dawn Lyn) has a slumber party with her friends.

Chip's (Stanley Livingston) old friend, John Simpson (Micky Dolenz), who's now a big rock star, pays a visit. Soon, Chip tells the family that he's decided to give up his studies and become a rock star, too. The family is extremely concerned--until John mentions that he makes $2 million a year.

Steve's boss and his wife count on the Douglas family to help them deal with their rebellious teen-aged son, Gordon (one of Ernie's classmates) after they suspect that the boy has fallen into drug use.