https://slate.com/culture/2005/07/owen-wilson-s-writing-career.html

Hey do you maybe know where this pic is from? This is literally on the minus man set .,, I cannot find a source,,, TnT

These are the only two pics that actually exist

(from @ocw-archive)

And the one I originally asked about is only on the one specific Pinterest post.

Jupiter Kissing Ganymede, Roman Forgery by Anton Raphael Mengs and Giovanni Casanova (c. 1758)

The faking of antiquities was a common practice in the modern history. It was often conducted by unscrupulous artists and dealers who sought to dupe gullible tourists and collectors.  This notorious 18th-century forgery, however, was created as a prank rather than for profit. 

In 1760, this fresco of Jupiter embracing his cup-bearer Ganymede, was said to have been ‘rediscovered’ in an ancient villa outside of Rome. German art historian and antiquarian, Johann Joachim Winckelmann was alerted of the fresco’s existence through his friend Giovanni Casanova, a Venetian painter and illustrator of Winckelmann’s book on ancient art. Winckelmann purportedly found the fresco so beguiling that not only did he accept the fresco as authentic, but included the fresco in his book on ancient art. He gave the piece lavish praise as a most wonderful and beautifully executed fresco.

Jupiter’s Favorite [Ganymede] is without doubt one of the most beautiful figures to survive from antiquity, and I can find nothing to compare with his face; so much sensuality radiates from it that his whole life seems to be nothing but a kiss.

Soon after the publication, Winckelmann began to suspect that he was tricked. Furious and humiliated, he called Casanova a scoundrel who sought to ruin his reputation as an art expert. Winckelmann never learned that Casanova worked together with their close mutual friend, Anton Raphael Mengs, to create the fresco. Mengs himself confessed to being creator of the infamous forgery on his deathbed in 1786.

There is a debate among art historians about whether the prank had malicious intent. Winckelmann was openly homosexual and was desperately enthusiastic to find examples of homoerotic scenes in ancient art, a fact that Mengs would have known as a close friend. Others have argued that Mengs created the piece as an experiment to demonstrate his belief that the Romans had painted with the Buon Fresco technique.

Despite being deceived by this forgery, Winckelmann is celebrated as one of the founders of scientific archaeology and art history. He was also one of the first to articulate the difference between Greek, Greco-Roman and Roman art.