This won't please some people to hear, but I'm not in the business of holding my tongue.
There's a lot of grief heaped on people who don't seek OOC pre-consent for RP of questionable topics, and this fails to address the fact (not supposition, but fact) that there are and always will be players that want these types of RP to be spontaneous, that want to be able to say 'No, no' while thinking 'Yes', that want to be able to safely experience the thrill/horror/joy/disgust from their well-lit bedroom desk hidden behind an anonymous screen from which they can walk away at any point if they so choose.
I'm not arguing against the idea that it'd be healthier for them to be able to OOCly say 'I want X', I'm just saying that for some, that takes the excitement out of it in ways I'd imagine are similar to if a scary movie flashed a warning on the screen to let you know a jump-scare is coming. The same way the ominous music is a low-key warning something is about to happen so you might want to cover your eyes and peek through your fingers, most RP of a 'problematic' nature tends to have a build-up to it during which you can measure and weigh your options and decide if this is right for you.
There is no one-size-fits-all for consent in fiction, what's important is to know your own limits/boundaries and enforce them to your own level of comfort. No one can force anyone to RP anything. I repeat, no one can force anyone to RP anything. They may try, but your keyboard + mouse + mental well-being are in your hands, literally.