This phrase refers to some collaboration that occurs easily and benefits all parties.

Theidioms says the origin is unknown. The christunitedfellowship suggests Genesis 2:18-25 is the inspiration, which begins

The Lord God said, “It is not good for the man to be alone. I will make a helper suitable for him.” New International Version

Wikipedia also suggests a biblical origin, though not a citation for the specific phrase.

Jews have held an ideal standard for Jewish family life that is manifested in the term shalom bayit. Shalom bayit signifies completeness, wholeness, and fulfillment… In Jewish culture, a marriage is described as a “match made in heaven,” and is treated as a holy enterprise.

But I’m pretty sure the first use wasn’t the 1977 movie A Match Made in Heaven

When you’re hit out of the blue, something (usually bad) happens without warning. I assumed this phrase refers to aerial bombing during a war. But Phrase Finder say it comes from an older “bolt from the blue” referring to lightning.

The earliest citation is Thomas Carlyle, in The French Revolution, 1837: “Arrestment, sudden really as a bolt out of the Blue, has hit strange victims.”

Another variation is “out of the clear blue sky.”

Word Detective offers this thorough definition:

‘To throw someone under the bus’ is defined as meaning to sacrifice; to treat as a scapegoat; to betray, but I think the key to the phrase really lies in the element of utter betrayal, the sudden, brutal sacrifice of a stalwart and loyal teammate for a temporary and often minor advantage.

Not all our popular phrases come from the King James Bible or Shakespeare – there is, apparently, no antecedent phrase about throwing someone under the wagon. This phrase belongs to us, so you’d think its origin would be clear. You’d be wrong.

Merriam Webster says:

The origins of throw someone under the bus have been attributed to minor league baseball, Cyndi Lauper, the slang of used car salesmen, and various other improbable sources…

The 1984 quote from rock star Cyndi Lauper where she uses the phrase “under the bus” (without “throw”) may or may not count as a sighting, according to Word Detective.

But Merriam Webster attributes the earliest written usage to Elinor Goodman, Financial Times (London, Eng.), 10 Dec. 1980:

Some still pin their hopes on the “under the bus” theory which has Mr. Foot being forced by ill health—or just the pressures of the job—to give way to Mr. Healey before the next election.

This, however, lacks the malevolent flavor of current usage. A better citation comes from Julian Critchley, The Times (London, Eng.), 21 June 1982, but a completely satisfying citation has eluded me.

So I must conclude that, while a recent phrase generates a lot of possibilities, it isn’t any easier to pin down than a venerably aged phrase.

Our own RF_alum’s children’s book about pigs – smart pigs, no lipstick

The futility of decorating a pig leads to more than one phrase. For example, trying to dress a pig in a gown only ruins the gown and annoys the pig. Or “you can’t make a silk purse from a sow’s ear,” which dates back at least to the mid-16^th century. But today I looked at putting lipstick on a pig – the futile attempt to make superficial changes that don’t fool anyone.

Slate’s Explainer says A Classical Dictionary of the Vulgar Tongue (1796) included a “hog in armor” phrase similar to our modern meaning, but the lipstick variation is recent:

In 1985, the Washington Post quoted a San Francisco radio host on plans for renovating Candlestick Park (instead of building a new downtown stadium for the Giants): “That would be like putting lipstick on a pig.”

Ginger’s phrase of the day agrees.