I haven't read this manhwa and only saw your comment on homepage, but I am assuming you are talking about what's called 'sounding'. It can feel good but you need to start slow and steady and get used to it overtime. Many people in the bdsm scene do it, but you need to be very careful, of course.
This is also why I find bdsm in manhwas quite cringe because ain't no way someone isn't coming out of that with some kind of trauma if they are suddenly made to do all this, with absolutely no mental/physical prep.
I can feel the pain through the screen. I thought that thing was for masochists, I never knew it felt good
It kinda is for masochists, so that part checks out. I won't recommend people to try it out on a whim though lol.
Genuine question like doesn't it hurt having that thing in your piss hole? Does anyone have any experience? Does it feel good??