Kelly is anxious for her uncle to be active in the PTA at the school. But Uncle Bentley has other things on his mind - a series of dates with a gorgeous actress.
Bentley has been living a double life: by day he is Uncle Bentley and by night after Kelly goes to sleep he is Bentley the ladies man. When Kelly plans to attend a weekend outing with her Girl Scout troop Bentley reluctantly agrees to escort Kelly to the meeting place and once there encounters glamorous Miss Hesselroth, Kelly's scout leader, whom he quickly begins to wine and dine. However, Kelly becomes concerned when she learns Miss Hesselroth is engaged to another man.
Bentley and Peter are both getting fed up with Kelly not cleaning her bedroom. After begging and pleading with her, Bentley becomes convinced that he needs the assistance of a psychiatrist in teaching Kelly responsibility. The doctor he chooses turns out to be a breathless beauty and he decides to discuss his problems with her over a candlelight dinner. Meanwhile, Bentley soon lets things get out of hand when the mess begins to spread from Kelly's bedroom to the whole house.
Kelly is in awe of her Uncle Bentley and asks him to take her out on the town on a real "grownup" date and Bentley promises her that he will take her out to a fancy restaurant. Meanwhile, Bentley learns of an important attractive lady client has come to town and he gets so wrapped up in business that he completely forgets his promise and making it up to Kelly may be a little bit harder than he thinks.
Kelly is trying to get into a prestigious girls club, "The Lucky 13s" and she is stunned when a girl on the board votes against her. Later, Bentley learns the reason behind the rejection is that the member who voted against Kelly has an aunt who dislikes Bentley. Bentley sets out to right a wrong, convinced that he must have wined and dined and then jilted the aunt, but trying to determine which aunt is which, is the trick.
Bentley becomes concerned about Kelly's inability to take care of her belongings and feeling that she needs a little feminine interaction; Bentley hires a housekeeper to help straighten her out. However, Bentley fails to reckon with the resistance Kelly and Peter can put up with, but it turns out that Bentley is the one that becomes fed up with the latest housekeeper, Mrs. Farrell, who totally insinuates herself into every facet of Bentley's home life and begins to interfere in his love life.
Kelly has her friends over and the fact that Bentley is acquainted with numerous famous people and movie stars comes up in conversation and not wanting her friends to think she is all talk, she promises that Bentley will be able to get singing teen idol, Ronny Mann to make an appearance at a party that she will be giving. This leads Bentley to attempt to produce the young singer to avoid a big letdown for Kelly but trying to get a hold of the singer proves to be a challenge.
When Kelly asks permission to babysit, Uncle Bentley refuses, claiming she's too young. But Kelly persists and finally Bentley relents and even looks in on his niece during her first assignment.
Kelly has been busy with ballet lessons, piano lessons and tennis lessons and when Bentley learns that a talent contest is being held at Kelly's school he encourages her to try out. However, after speaking with each one of her instructors, he discovers Kelly is lacking talent in all of those areas. Kelly quickly tries to come up with a talent but she becomes convinced she has none. Meanwhile, Bentley must deal with the competitive fathers of Kelly's "talented" classmates.
Uncle Bentley becomes concerned when Kelly suddenly begins to spend all of her free time with the Fuller family. Bentley gets fed up with Kelly constantly raving about Mr. Fuller and all the great things he does to entertain. Bentley soon turns it into a competition and sets out to wins Kelly's attention himself and he turns to Kelly's favorite comedian Jack Benny for a little assistance but even Jack Benny may not be able to break the Fuller spell.
Bentley gives his permission to Kelly to go out on a date. Then he learns that she plans to go out with the son of a friend of his.
Uncle Bentley has been busy wining and dining a movie star, Liza Lane who just adores Peter so when she asks if she can borrow him for a couple of days, Bentley agrees to lend him to her. However, with Peter gone, Bentley soon realizes just how much he has come to depend on Peter. Meanwhile, Bentley secretly plans a candlelight dinner with a new client and with Peter away hires a replacement to serve but everything goes awry as the replacement he hires turns out to be part of Liza's revenge plot.
Bentley decides that it is time for Kelly to have some stability in her life and he decides to officially adopt her. Convinced that it will be a simple legal matter, Bentley is not quite prepared when he learns a social worker appointed by the court will drop by unannounced to witness the home life of the child. So Bentley, Kelly and Peter camp out waiting to impress the social worker. However, Bentley's not being able to control Kelly and also his "bad" habits may be his undoing.
Bentley gets fed up when it seems everyone is playing matchmaker for him and fixing him up with every single woman in town. Bentley is caught off guard when Kelly joins the bandwagon and begins matchmaking and she plots with her friend Ginger to pair Bentley up with Ginger's single mother and all goes well. Bentley hits it off with her and Kelly and Ginger have hopes of becoming sisters. However, after all their attempts Kelly makes realizes Bentley does not love her and the girls begin plotting to break them up.
Kelly is excited about going out on her first real date with a boy but Bentley is anything but excited and is worried about what could be on the mind of her boyfriend. Despite this, Bentley lets her go out with him to the school dance and she promises to be back at a reasonable time. However, Bentley spends the entire night at home with a lady friend, worrying and then becomes frantic when Kelly does not arrive home at 11:15, this prompts him to scour the neighborhood in search of his missing niece.
Kelly begins to take a larger role in the household and becomes a regular little homemaker, complete with cooking meals. Meanwhile, Uncle Bentley's latest client is Ronnie Burns; son of George and Gracie Burns and Kelly and her friend Ginger are dying to meet him. Kelly manages to get Bentley to agree to bring him over for a dinner that she is going to prepare but her plans may be dashed when Bentley's plans change and he forgets all about Kelly's dinner.
Spring has sprung and love is the air and Bentley is in for a bumpy ride as Peter has fallen in love and has been spending all his time with his girl, while Kelly has an eye for a boy and even Tramp has been hanging out with a neighbor dog, Bentley finds himself loveless. So Bentley decides to call Barbara a woman whom he certainly would end up with marriage. Meanwhile, Bentley begins interviewing new secretaries as Vickie has announced her engagement.
Uncle Bentley meets Kelly's latest boyfriend, Howard, and Bentley quickly finds that he can't get him out of his hair. It seems everywhere Bentley turns, there is Howard and Bentley tries to come up with a way to get rid of him but in the end he decides to pretend to like him in a ploy for Kelly to lose interest. Bentley's plot works, however, Kelly decides to keep Howard around solely because she believes Bentley likes him so much.
Uncle Bentley has gotten used to coming home from work and finding the house filled with Kelly's friends. However, when her friends begin exhibiting a lack of discipline, their mothers begin to refuse to allow their daughters to visit the Gregg household. This leads Bentley to invite the mothers over to explain the situation and soon he finds himself coming home everyday to a group of mothers who are looking for socialization, but now Bentley has another problem, the fathers are not willing to take this lying down.
Bentley has a friend, Joe Browning, whose wife Irene, is a non-stop matchmaker who makes it her goal in life to get Bentley married. After a few failed attempts, Irene secretly plots to have an attractive woman move in next door to Bentley and play hard to get and her plan seems to work, when Bentley falls head over heels for her. However, Bentley begins to have second thoughts when the idea of children enters the picture.