Houseboat is basically a charming mashup of, like, Sabrina, Roman Holiday, and The Sound of Music. But with the aesthetic of Move Over Darling.
Cary Grant is Tom (Tom? Come on, he may be a Peter, a Brian, a Mortimer, a Dudley, a C.K. Dexter, but a Tom he is not), an absent father who returns from mysterious “government work” (clearly he is a spy) to take custody of his three children after his estranged wife is killed in an accident. His in-laws want to keep the kids (and, incidentally, separate them, because even though they live in a huge mansion and seem to have already had the kids living with them for months or years, they apparently don’t have room for both boys and one girl in the house).
He takes the kids to his flat in Washington D.C., only to discover that they are fairly messed up after the death of their mother and being semi-kidnapped by the father they barely know. David steals and peeps at naked ladies, Elizabeth can’t sleep, and Robert runs off and constantly plays the harmonica (yes).
But when Tom he loses his youngest son after a concert–incidentally inviting runaway socialite-turned-nanny Sophia Loren into their lives–
he decides they’d be better off in his sister-in-law’s country guest house. (She’s played by Martha Hyer, reprising her role from Sabrina as the lovely, appropriate, but ultimately un-lust-inspiring castoff). Alas, when the house is run over by a train (yes) the family + Sophia have no choice but to move into…you guessed it, a dilapidated houseboat!
The kids are surprisingly un-irritating, and the story actually takes a rather gentle and thoughtful look into the different ways they handle their grief and carry on with their lives. They slap some paint on the boat, CG learns to value his family above work, and the family finds their feet.
Then some snobby people–not realizing that Sophia Loren is no mere nanny/mistress, but actually the daughter of a world famous orchestra conductor!–are very rude to her at a fancy party that might actually take place on the set of the Larrabees’ patio from Sabrina. Naturally, this causes Cary Grant to realize that–of course!–he loved her all along. So she borrows Audrey’s wedding dress from Funny Face, the spurned sister-in-law acts as maid-of-honor, and they get married right on the boat. The kids, who love Sophia as a nanny but aren’t so sure about her as a mom, begrudgingly come around.
Best of all, it features this fabulous, uplifting ditty:
It gets a Bing! Bang! Bong! in my book!