Danny and Kathy with three children along take a delayed honeymoon in Las Vegas but Danny draws the family's ire by entertaining spontaneous crowds against his pledge that this was to be a non-working vacation.
Terry has been running the household since her mother's death: managing meals, shopping, laundry, and looking after her father. Kathy tries to explain gently that she is taking over running the house, but Terry isn't giving up her position without a fight.
Danny's Uncle Tonoose comes to town to meet his new niece-by-marriage, Kathy, which is actually an inspection to determine whether she will be officially accepted into the family. Unfortunately, Uncle Tonoose's shabby treatment of Kathy seems to indicate that he does not approve of her.
Danny and Kathy are told they are an old established couple who are content to stay at home and relax. They decide to show that they can be just as active as other couples by cramming in one activity after another.
Kathy's father was away on a 3-month trip when Kathy and Danny got married. They didn't want to wait, and her father's not happy he wasn't at the wedding. As a matter of fact, he isn't happy with Danny at all. Rusty doesn't understand why Danny is putting up with all the insults and bad behavior. Danny tries to explain that Mr. Daly is Kathy's father and his elder and deserves his respect.
Rusty finds a wallet and Danny explains to Rusty that returning it to him is the right and honorable thing to do. Danny accompanies Rusty to the man's apartment and Rusty is expecting that the gentleman will give him a reward. Danny convinces Rusty that he still acted honorably, irrespective of whether or not he was compensated for his honesty. At that moment, the doorbell rings and Rusty receives a very nice surprise.
Terry is very excited about her new part time job in a dress shop. However, the bloom is off the rose when Terry complains about an aggressive co-worker, who manages to get to customers before Terry has a chance. Danny intervenes when he sends a decoy, a girl from the Copa, to the shop, in order for Terry to make a hefty sale.
Terry and her friend Peggy are hoping to join an exclusive sorority at their high school, but Terry is refused membership because her father is in show business, which is considered lower-class by the the snobbish social club.
Rusty announces he is entering the Soap Box Derby. Danny and Mr. Daly go down to the basement to help Rusty, but argue over the design and each end up building their own cart. They are so busy arguing that neither notices Rusty has left the basement.
When a man at the Copa is forced to give up his dog, Danny brings the pup home to Rusty. Rusty is thrilled, but when the man comes to visit the Williamses, Rusty sees how attached he is to the pup and how much the pup is attach to the lonely gentleman. Rusty realizes he can't keep the dog and figures out a way to reunite the pooch with his former owner.
Kathy's uncle Sean is coming to visit Kathy and her new Irish husband. Kathy isn't the only one to stretch the truth; to get out of losing a chess game Uncle Sean has Danny send word back to his old foe Paddy McCormick in Dublin that he's died. Now Paddy's coming for the funeral. SONG: It's the Same Old Shillelagh.
Liz thinks Danny will be thrilled with her good news -- she's booked Bob Hope for a benefit Danny is doing for the Heart Fund. Danny hits the ceiling when he hears the news, convinced that Bob Hope will do all that he can to steal the show out from under him.
On the day on which he is opening his show at the Copacabana, Danny is afraid to see or be served by 'Evil Eye' Schultz, a waiter at Lindy's Restaurant with a reputation for jinxing anyone's opening night performance if he serves them that day.
In Lindy's Restaurant, Danny tells waiter Oscar Schultz (nee 'Evil Eye'), who is getting married to a woman with children, why not to take the children along on the honeymoon. Danny's own difficult honeymoon with the children is shown in flashback.
Danny gets annoyed at the imperious Mrs. Greenson, head of Kathy's ladies' club, when she suggests that Rusty is incapable of selling more raffle tickets than her son. Danny picks up the gauntlet and uses his nightclub act as a venue to help Rusty exceed all expectations. Danny and Kathy have second thoughts, however, when they consider that Danny's tactics give Rusty an unfair advantage and that Mrs. Greenson's son is very diligent and works tirelessly to sell his tickets.
Rusty is being bullied at school. Danny takes Rusty to his gym where he has fighter Max Baer teach Rusty to box. Unfortunatley, when Rusty becomes the bully Danny and Max have to find a way to teach Rusty not to fight.
Danny returns from an entertainment tour and just wants to stay home and relax for a while. However, Kathy has signed him up to be the director and producer of a charity show at the hospital where she worked - without asking him first.
The school is having an awards ceremony and the fathers are invited to say a few words. Rusty is receiving an award and Danny is going, but Rusty's friend (played by Johnny Crawford) is going alone to get an award for "Best English". When Danny goes to the shoe repair shop to persuade the father, he finds out the real reason the father isn't attending. Danny gives a touching speech on emigrants at the ceremony.
Danny is alarmed to learn that Terry has been spurning classmate, Donald Cooper, in order to swoon over Dean Martin. Danny enlists Dean to figure out a way to place his wayward teenager back into the arms of the hapless, but far more suitable, Donald.
Terry's friends have band practice at Danny's house, preparing for a PTA show. Danny protests because it is rock & roll and not real music. When Danny finds out the principal cancels the band, Danny starts supporting the band's music.
When Terry has trouble acting her part in The Merchant of Venice and Danny is unable to help her, Rusty finds a erudite beggar in the park and presents the beggar as a drama coach but Danny is skeptical of the man's qualifications.
When Rusty complains that Linda tags along with him, wherever he goes, Danny reminds Rusty that Linda is his sister and that families should do things together. Kathy overhears Danny's lecture and suggests that she accompany Danny to his poker game that night.
Danny notices that Rusty is very impressed that his friend's father is an a prominent attorney. Sensing that Rusty may be ashamed of Danny's show business career, Danny invites his son's friends to watch him perform, hoping to garner Rusty's respect for what Danny does each night at the club.
Danny is not at all pleased with Terry's new and very wealthy teen aged friend, Connie Coleman. She's very uppity, dresses like a chic and much older woman and has Terry putting on airs. When he encounters Connie's parents, he learns that they are globe trotters and care very little about their daughter. Mindful of this, Danny's views towards Connie change and he urges the Colemans to pay greater attention to their daughter, who loves the Williams household for the love, care and concern exhibited towards Terry there - and for what what's lacking in her own home.
When Liz signs a beautiful blond dancer, Dawn DuBois, as part of his new act, he's convinced that Kathy will become insanely jealous of the young woman. When Liz protests and Kathy exhibits great enthusiasm and praise towards Dawn, Liz is vindicated in her estimation of Kathy, much to the upset of Danny. But is Liz right or is Kathy playing possum?
Rusty is hell bent on finding a job, to prove to his father that he doesn't need an allowance. Danny protests, but relents at his son's determination to earn his own way. Rusty shines shoes, but when he encounters a needy boy who polishes shoes because his family relies on his income for groceries, Rusty gives the boy his earnings. What Rusty doesn't know is that his act of generosity is witnessed by Kathy and Danny, who tells his son he has earned his respect and acknowledges his entering manhood.