Why, “the little death” of course. Also known as:
An orgasm.
The expression is by no means vulgar, but isn’t neutral either and definitely not an euphemism. It is descriptive.
For example, you wouldn’t use “Wasser lassen” when you’re participating in a day-long assessment center for a new job or you’re in a meeting of your local church council with your pastor and some elderly ladies.
I see, you’re right that it doesn’t fit the definition for euphemism, and that it would be unusual to use in situations like you described, although not “rude” IMHO (though the old ladies and the pastor surely would think you’re funny if you used it).
I don’t think of those as euphemisms. They are just normal, non-rude words. A euphemism actively tries to conceal the rudeness or inappropriateness of the action.
So instead of “I am urinating!” you would say “I am currently somewhat indisposed”. In this case, “indisposed” could mean anything, but you know what it means. So the speaker has managed to get the meaning across without referring to the icky bodily function. “I’m urinating” is just a slightly less vulgar way of saying “I taking a piss”, but not a euphemism, AFAIK.
Well, be that as it may, I was wondering if other languages were similar in this respect.
Rob
I agree. “Rude” is the wrong word. But it could be, in a number of situations, be judged as lacking, to some degree, the formality which would have been expected.
Ah, ok. Well, in Dutch:
Urineren - more formal than “plassen”.
Menstrueren - more formal than “ongesteld zijn” (and more accurate)
In Portuguese:
Urinar - more formal than “mijar”
Menstruar - more formal than…uhm… euphemisms and colloquialisms.
I’ve been looking at this copy of O, Loca Tu Ibis, a fairly shabby translation of Oh, the Places You’ll Go into Latin. Although there’s little to criticize in the straightforward translation of the title, I am amused that loca can mean a woman’s genitals, and the verb ‘to go’ can carry the same import as the English word ‘come’.
Many of our literal sexual terms come from Latin euphemisms. Penis once meant ‘tail.’ Vāgīna was a sheath for a sword or dagger. Ānus, which originally just meant ‘ring’ was used so often to refer to the asshole that even by classical times they had to start using the diminutive ānnulus to refer to other kinds of rings. Fornix was the Latin term for arches, which were often used on the first floors of buildings and these floors so frequently housed brothels that the Romans switched to the term arcus for the architectural feature and fornificātiō went on to become an English word for sex.
Facere, ‘to make or to do’ can mean to piss, shit, fuck or simply substitute for any other indelicate verb.
Pecten, ‘comb’ was used to refer to the pubic hair, and evolved into the Spanish word pendejo.
Hi Rob, i’m italian and I confirm you that in Italy we have the same euphemistic use in those fields.. 
to urinate/defecate: “andare in bagno”-> “I have to go to the toilette”
to have sex: “andare a letto”
etc.. etc
all languages uses euphemistic words to say something in a politer way..
other arguments are so forbidden in a language that the speakers use to paraphrase it..
Les papillions d’amour?
Le mot de Cambron?
Yes. Yes, they do.
Johnny Angel, I submit for you the artist and his tools:
Primum opifex, altus prosator, ad terram viviparam et cuncti- 14
potentem sine ullo pudore nec venia, suscepto pluviali atque discinctis 15
perizomatis, natibus nudis uti nati fuissent, sese adpropinquans, 16
flens et gemens, in manum suam evacuavit (highly prosy, crap in his 17
hand, sorry!), postea, animale nigro exoneratus, classicum pulsans, 18
stercus proprium, quod appellavit deiectiones suas, in vas olim 19
honorabile tristitiae posuit, eodem sub invocatione fratrorum gemino- 20
rum Medardi et Godardi laete ac melliflue minxit, psalmum qui 21
incipit: Lingua mea calamus scribae velociter scribentis: magna voce 22
cantitans (did a piss, says he was dejected, asks to be exonerated), 23
*demum ex stercore turpi cum divi Orionis iucunditate mixto, cocto, 24
frigorique exposito, encaustum sibi fecit indelibile *(faked O’Ryan’s, 25
the indelible ink).
Like gracer, I wouldn’t think of those as euphemistic, but technical. Pee is not the technical term, the one you’d hear a doctor say, but it’s also not “the kind of word you wouldn’t use in front of your dear grandmother”. And yes, other languages have technical terms too.