"If you love something, set it free. If it comes back, it's yours. If it doesn't come back, it was never yours to begin with. But if it just sits on your couch, eats your food, watches your TV, and uses your phone, and doesn't seem to realize or care that you set it free, you either married it or gave birth to it."
—A parodic twist on a well-known proverb
This is where in a married couple, the husband is child-like and the wife is like a parent to him except that she can quite easily provide him sex. Sometimes, the wife may talk about feeling like she really does have one more child than the number of children they have, and guess who the extra is? Ironically, her job of child care may be made easier by the husband being able to connect to their children more effectively.
Sometimes, this is part of a Closer to Earth setup, with a Bumbling Dad. He may also be a Henpecked Husband, or he may just have a penchant for causing wacky hijinks that his wife must resolve. Sometimes, the husband is perfectly angelic or a hard worker, or a mixture of the two, and the wife is simply motherly with no shallow motives.
A rather awful Double Standard; the notion of a girlish wife in need of control and protection by a fatherly husband rarely appears today but this one persists. There are Unfortunate Implications on both sides - men are told that they're useless and incompetent, at least in the realm of family life, and should really just let their wives take charge; women are told that they can't expect their husbands to act like grownups and should just resign themselves to always having to be the boring, responsible killjoy in the family.
In Dragon Ball, Chi-Chi treats her husband Son Goku very much like this. However, it could be subverted, as the fact that Goku is a phenomenally powerful alien Martial Artist makes this relationship look more equitable than most other examples — Chi-Chi "takes care" of Goku at home, Goku "takes care of her in return"... by saving the world on a regular basis.
Baron and Baroness Bomburst in Chitty Chitty Bang Bang. She buys the man toys, for God's sake, and coos over him as if he were a precocious, temperamental infant. (Which, admittedly, he totally acts like.)
This is one of the issues at hand in the film The Story Of Us.
Taken to a rather Squicky extreme in Merlin's Shop of Mystical Wonders: The Jerkass critic in the first story, as a result of a spell gone wrong, turns into a baby, giving his infertile wife the son she could never conceive. Needless to say, when this movie was featured on MST3K, this did not go un-mocked.
Mike: Oh, good, now she has to raise her horrible husband!
Crow: That's what most wives think they do, anyway.
When the doctor in Blindness goes blind, his wife ends up treating him more like an infant than a spouse anymore, and it repulses him.
A gender-reversed version of this occurs in Charles Dickens' David Copperfield, in which David's first wife is childlike and asks him to think of her as his "child-wife."
In Diana Wynne Jones' House of Many Ways, sequel to Howl's Moving Castle, Howl actually turns himself into a Deliberately Cute Child, and poor Sophie has to deal with both him and their son. While trying to do her job.
In the Moomin books, Moominmamma to Moominpapa. In the comics she openly laments how hard it is to have a husband that never grows up.
Most modern sitcoms. (50 or 60 years ago, however, you were more likely to see the reverse.)
Desperate Housewives has Tom and Lynette Scavos. Lynette often has to play the bad guy and suffer through being the disciplinarian while Tom is the cool Hot Dad.
Though, in fairness, they showed him as the grownup one just as often, especially later on when her craziness was flanderized.
How I Met Your Mother has Lily and Marshall. There's even one scene where Ted and Marshall are standing in front of Lily with their heads bowed like little children getting punished and saying "Sorry, Mom Lily" together.
This one goes back and forth and around, though, as Lily is often shown to be immature and occasionally infantile as well as the others. Taken to an extreme in one particular episode where Lily is convinced that Marshall is ready to raise a child because he was able to take care of her when she was drunk and acting like a child. The same episode was also one of many to point out that Ted is basically already a dad without kids (or a wife, for that matter).
In Brit Com2Point4Children, I'm fairly sure that the 'point 4' is supposed to refer to the husband.
The Cosby Show, though Cliff Huxtable is not a Bumbling Dad, and this one possibly isn't an example of Closer to Earth; Clair Huxtable was more practical but not really morally superior, and in fact was sometimes *indrawn breath* wrong.
Believe it or not, the parents of the Toad family in Westmost house in Toad Town of Paper Mario manages to fit this trope. The wife mentions in one of her conversations that she feels like she has three children.
Matsu to her somewhat slow but endearing hubby Toshiie in Sengoku Basara.
Family Guy: Lois and Peter Griffin. One episode even had a scene where he was refusing to brush his teeth and she would've had to do it for him if they hadn't heard burglars breaking in at that moment.
Announcer: Attention, Marge Simpson: your son has been arrested. Announcer: Attention, Marge Simpson: we've also arrested your older, balder, fatter son.
King of the Hill: MAJOR inversion with Hank and Peggy Hill. Peggy's huge ego makes her act ridiculously childish, forcing Hank to clean up the inevitable mess.
