Description:
Exploring a new age phenomenon that's been bugging me for some time - increasingly so I am afraid.
I can't make heads or tails but tales of it, though. The reason for that may be self-evident. 
 

Appropciation 
Say I travelled to far away country where they speak a language I don't understand, let alone speak. 
We've all been there, maybe not the particular country in question, but the far away place with the foreign lingo.
Except, of course, the locals, those indigenous to that country because due to geographical, nay socio-economical laws they're more than likely too poor to visit our realms (i.e. Western World - even though they might be located farther west (but also farther south) when looking at your basic map of the world).

Say despite all that I managed to, with a thick accent and a somewhat off pronunciation I managed to scramble together half a sentence that amounts to something akin to "I love you beautiful lady" and as the story goes one thing led to another from there. 
And whilst nothing more than a night or two spent together came of it, no harm, no foul, it was, for lack of a better word, an enriching experience for everyone involved. Maybe satisfying would be a better word, on second thought. 

Say I return home after my stay there and anecdotally or graphically retell the little, ultimately rather trivial story to an acquaintance in what wouldn't be a considered a private place such as a public house, a bar, a train or wherever it is that people tell each other of such encounters.

Say someone overhears this and finds something objectionable about the tale. Be it perceived exploitation in what was for all intents and purposes a mutually agreeable exchange of bodily fluids. Or be it an objection to excessively graphical nature and/or possibly obscenely colourful language 
deployed in the retelling of the experience or anything else to that extent that should or at least could easily be refuted by inviting the forth party to mind their own business and/or encouraging them to consider obtaining a life of their own (or at the bare minimum one that's less boring 
than the one they ostensively inhabit at that given time).
It might be more appropriate, however presumably highly ill-advisable to tell that person to fuck off (especially if they voiced issues about the language already). It would hardly put you in the wrong though to say that to express your own discontent at being interrupted by a stranger. 
Because that's just rude - irrespective of how you twist and turn and justify the intrusion.
 
No matter how much you misspell the word self-righteous - you can't spell it without the word self (which incidentally is the same word used in
the expression 'go fuck yourself'. And if you somehow manage to spell self-righteous without an using s+e+l+f, then one has every right to ask what the fuck you are talking about and tell you to go fuck yourself. Unless one feels smart about and proffers a 'do I need to spell it out for you?' instead.
Albeit deploying such tactic might result in being misunderstood completely and/or having produce a pen and paper to deliver the promised goods. It is therefore good advice to carry these instruments of communication with you at all times - just in case - one can never anticipate the lostness of those one might encounter.

Say the offended fourth party ups the stakes and proclaims that the use of mentioned foreign phrase or any other phrase in that or any other equally foreign (i.e. foreign to place the exchange takes place) language constitutes what's come to be known as cultural appropriation. 
Despite the fact that it was in the local language where it was initially said. Despite the fact that person you said it to appreciated it and by their own admission found it cute.
And despite the fact that it had desired effect (i.e. got you laid). 

What on earth do you say then?

Where to does cultural appreciation end, where does cultural appropriation begin?

And why in the twelve names of fuck are there people so bored by their own hollow existence that they have nothing better to do than attempting to draw that line?

To paraphrase a line from one my favourite movie characters: there are some things I will never ever ever ever ever ever fucking understand!
Note: that line was said in English -> I wouldn't want to piss off anyone by mistranslating from a language I do not understand.

Additional note: in the event that someone should ever take offence from this purely hypothetical example I'd be forced to advise them to take
their purely fiction outrage elsewhere, lest they'd be told to fuck off in languages they do not understand.
Although, admittedly, these two are (unlike the aforementioned appreciation and appropriation) are not mutually exclusive.