Your reply includes terms of offense I never used or even implied. Not being a person of a like mind does not connote inferences on intellectual levels. I have written I was not going to keep unwanted company, which is a form of bidding adieu. First, I answer your argument.
The online etymology dictionary you quote gives 1784 for the date of the ‘droit’; the date is obviously not Medieval. The Free Dictionary goes to 1815-1825.
There is no evidence from the Middle Ages. Some ‘researchers’ try to quote the ancient Mesopotamian ‘Gilgamesh’, which is obviously neither French, nor Latin.
The ‘Latin equivalent’ you find perfectly reasonable would be much nonexistent. Perseus is a very extensive source for Latin.
“Ius” returns 459 results; “Ius primae noctis” returns 10 results, none of them rendering the mythical ‘right’;
‘jus primae noctis’ does not return any results; “jus” alone hardly returns any results, all the three coming from times later than the Antiquity
What one would be left to is the Wikipedia and the painting “Le droit du seigneur”, again, dated to 1874 and Vasily Polenov, member of the painter movement to become precursor to Socialist realism.
Rape might be not nation-specific. The practice of a mythical precedent can dated back in England to the times of Elizabeth I.
You mention religion. The psychologically significant fact is that ‘Seigneur’ remains the French term for the ‘Lord’, meaning the God. Should there have been an established practice of rape, either French landlords would have become termed ‘earthenlords’, or the God would have become ‘the Archon’, whichever you consider more likely.
Bidding adieu is perfectly fine.