
Sincere question - do Doms normally slap the M during BDSM? Well, still made me uncomfortable. Idk I hate this storyline overall. Not sure how they fix it.

Some people are into that. Some people are into helllllaa weird shit. For instance, throwing up on someone, peeing on someone, blood , etc. it’s weird... so I guess slapping isn’t that weird compared to others. I think Chanwoo likes pain too, but I’m kinda worried I hope MD doesn’t take it to far. I don’t really think he would?? Idk.

The Dom can if it's been agreed upon. The core of BDSM is consent. Before any kind of play or even establishing a Dom/sub relationship, they have to discuss what their hard stops are, which can be "no slapping my face" if that's a no for the sub. So if MD did it, as a Dom, he has to be playing by their agreement. There's also the safe word which would stop that immediately if it's something the sub doesn't want to do. The first utterance of the safe word is an absolute dead stop, that very second. Anything past that is assault because it stops the consent, thus ceasing to be bdsm.
I said this on a different manhwa topic but this reminds me a little of The Breaker and Noblesse. I also love the mixture of action comic mixed with yaoi. We could do with a lot more of these sort of stories on here.