And your explanation is wrong, because you've confused two subcultures, as multiple people have tried to tell you.
You do your job poorly.
The fucking point has been repeatedly made: Slang of this sort wouldn't be used by Anglophones who engage in activities of these sorts nor in the closest Western equivalents. You might as well have them using Edwardian slang or cowboy slang.
And I'll complement that invitation with a suggestion that you not read comments criticizing your inept use of slang. Doing so would seem rather hypocritical.
I'll just copy what I pasted to other people, with a couple of edits, regarding the use of those two words and what the raws were;
For the word "Gyat":
The raw was "デッ!!" ("De!!!") Short for でかい ("Dekai") meaning "Huge!" But in a more exasperated exclamatory way (ie; the English "WOAH!"). I thought it fit him as a character to say it and it gets the same impression from when reading the raws, too.
I've had people say "well just use "huge" or "woah" then?" to which I say, saying "huge" sounds weird af, that's not a natural reaction. Saying "woah" would fit, sure- but I wanted a word that more fit with "surprise at the voluptuous size of something", so we have "Gyat". I know it's most often used to refer to the size of a woman's ass, because we're culturally in an "ass is king" period for sexual attraction, but from my research into the word and it's usage it can be used to refer to either ass of boobs. So it still fits.
For the word "rizz":
The raw was "モテ期"
モテ comes from モテモテ meaning "to be popular with the opposite sex (or of the same sex, if they're LGBT)"
and 期 comes from 期間 meaning basically "time", "period", "season" etc.
So a literal translation would have been "Are you having a period in which you're popular with the girls right now?" ....but fuck that when we have the useful "Rizz" word nowadays which means essentially the same thing.
So the problem being put to me is my use (or perceived mis-use by some) of English slang. I've explained in detail what the raws said and why I chose those particular words as they seem to fit perfectly for me.
For what it's worth, my purpose in commenting was to object to poor plotting, but then I found Yank-bashing in response to your use of shitpie slang, so I stepped-in because you rather clearly weren't a Yank. The fact that it was obvious that you weren't a Yank should be a strong hint to you that you've botched the use of the slang.
Yank-bashing? You don't mean me, right? Because I never did that. I have, however, seen people bashing the slang itself, on top of people bashing my use of those words (again, see above for my reasoning. But also, feel free to offer alternatives if you have such a problem with it?