I found this story in The British Chronicle, 15 September 1790.
If Doris Day didn’t star in some sort of 1960s bedroom comedy farce with a similar plot, I’ll eat my hat.
“The following circumstances created some buzz at a fashionable watering place last Tuesday night. Lord xxx, who had possessed a tenderness for the wife of his valet [Thomas] for some considerable time past, at length managed matters so well as to effect an appointment for passing the above night with her, and to that purpose previously sent her husband away to a town some miles distant, upon business which would have detained him until the next day. Thomas, however, suspecting the fidelity of his wife, put off his journey and concealed himself in an apartment adjoining his wife’s.
At the hour of assignation his Lordship quitted his Lady, and repaired to Mrs Anne [Thomas’s wife]; Thomas then shifted from his lurking place and having the key of his wife’s room in his pocket, when he found all quiet, very deliberately locked up the Peer with his enamorata [an archaic version or misspelling of inamorata, a female lover], and then repaired to his Lady’s chamber, where he filled the place his Lordship had resigned [Heh, ‘filled the place’. I see what you did there].
“In the morning, gentle readers, you may picture to yourselves the confusion of the whole family; his Lordship was found locked in the arms of Mrs Anne and her Ladyship was discovered in the same situation with Mr Thomas.”
A few notes: I’m pretty sure this never actually happened, largely because it’s not really news. Or at least it would have been news, had the author given a clue as to whom Lord xxx really was. Obviously no one is going to print his real name, but the names of the servants and the fact that they were all at a fashionable watering place wouldn’t be enough to hint at the peer’s identity, without which no contemporary reader would care.
Secondly, although masters and mistresses absolutely slept with their servants (made easier by their fashionably separate bedrooms or even whole apartments in the house), it’s extremely unlikely that a valet would have just approached his aristocratic employer’s wife for sex. You had me up until the point that he got revenge sex with an aristocrat.
Not that this couldn’t have happened, but that would have been one BALLSY thing to try. In all likelihood, she would have said no, fired him, and perhaps had him arrested. Messing around with class barriers like this could be very dangerous–generally speaking, the higher-ranked person made the first move, especially if the higher-ranked person was a woman.
Thirdly, I very much doubt that the lady in question would have risked her reputation by allowing Thomas to stay in her bed long enough to be caught by the maid the next morning. Even assuming they were both on board with revenge sex, it would be enough for the lord to be caught and embarrassed with Mrs Anne in the cupboard. There would be little-to-no reason for his wife to expose herself to a sexual scandal, as well. While the desire to reveal her husband as a cuckold could potentially be strong (in that it would embarrass and hurt him even further), this could lead to some extreme social and legal consequences for the lady.
Finally, any servant who had attained the extremely coveted rank of valet would have been very careful not to lose his job without a reference. Regardless of his wife’s fidelity, not carrying out the task upon which his master had sent him would likely result in him being fired without a reference. He would certainly lose his place for locking his master in a room all night, and he would definitely lose his place for sleeping with the lady of the house. I’m not entirely sure what Thomas would have done for work after that, as it would be hard to gain another position when you’re forced to leave your place of work in disgrace. Again, that’s not to say that people don’t impulsively blow up their careers for a variety of reasons, but it would have been far more difficult for him at this time in history to find similar work.
In all likelihood, this is just a really fun cautionary tale about the sexual degeneracy of the aristocracy and how the working class occasionally triumphs over them.