This is the only painting by Alexandre Charles Guillemot of which I could find a high-quality reproduction: Mars and Venus Surprised by Vulcan, 1827. Not a very convincing rendering of the story found in the fourth book of Ovid’s Metamorphoses, here in the translation of Garth and Dryden:

The Sun, the source of light, by beauty’s pow’r
Once am’rous grew; then hear the Sun’s amour.
Venus, and Mars, with his far-piercing eyes
This God first spy’d; this God first all things spies.
Stung at the sight, and swift on mischief bent,
To haughty Juno’s shapeless son he went:
The Goddess, and her God gallant betray’d,
And told the cuckold, where their pranks were play’d.
Poor Vulcan soon desir’d to hear no more,
He drop’d his hammer, and he shook all o’er:
Then courage takes, and full of vengeful ire
He heaves the bellows, and blows fierce the fire:
From liquid brass, tho’ sure, yet subtile snares
He forms, and next a wond’rous net prepares,
Drawn with such curious art, so nicely sly,
Unseen the mashes cheat the searching eye.
Not half so thin their webs the spiders weave,
Which the most wary, buzzing prey deceive.
These chains, obedient to the touch, he spread
In secret foldings o’er the conscious bed:
The conscious bed again was quickly prest
By the fond pair, in lawless raptures blest.
Mars wonder’d at his Cytherea’s charms,
More fast than ever lock’d within her arms.
While Vulcan th’ iv’ry doors unbarr’d with care,
Then call’d the Gods to view the sportive pair:
The Gods throng’d in, and saw in open day,
Where Mars, and beauty’s queen, all naked, lay.
O! shameful sight, if shameful that we name,
Which Gods with envy view’d, and could not blame;
But, for the pleasure, wish’d to bear the shame.
Each Deity, with laughter tir’d, departs,
Yet all still laugh’d at Vulcan in their hearts.

If you make a reverse image search, you will find countless websites, usually about medical themes, that have this image inlined, and it has been used for a book cover. Yet it took me quite a while to find out who the artist was.

This is strange, since it was the winning entry for the Prix de Rome in 1808, when the subject was once again (as it had been in 1774) Erasistratus Discovering the Cause of Antiochus’ Disease. Even though he won this prestigious prize, there is very little information about Alexandre Charles Guillemot on the web. He was born in 1786 and died in 1831, that’s about all.