Any Madame worth her salt and that wants to stay in their business to a ripe old age isn't going to ride without a glove in place. That is why she is a cum dumpster full of disease and is going to wind up in a dark alley somewhere with bums
Not that I want to defend Quinn or anything (I do think she's a trainwreck), but you can't say she wants to be a "madame" for any longer than she's going to be in school for.
As for being a cum dumpster, again, to be fair, we haven't seen her fucking around with anyone aside from the MC or girls. She's also not on her restaurant's menu, at least not yet.
I'm not saying she doesn't get pumped full by randoms on an hourly basis, but we haven't actually seen it, so there's no definitive proof. Maybe she really does like the MC like all the "Quinn is a goddess!" types think. Who knows.
Personally, I'd be far more concerned about the intravenous drug use and needle sharing she seems to be doing. That's FAR more likely to result in some diseases and actually is likely to end up with her in that alley you're talking about.
And yeah, if I was the MC I'd be getting my shit tested after that party, of course I'd be doing a lot of things differently as I'm slightly smarter than the average grapefruit, unlike our alter-ego.