No he really didnt- It was obvious that his sub was becoming gradually uncomfortable and he did nothing to act on that. No regular check-ups to see how he was holding up, no pauses or breaks- Which are often a fundamental part of BDSM. Maybe I don't understand BDSM as much as you clearly do, but I do know that a Dom is supposed to know what is best for their sub and treat them accordingly- And this clearly is not what was best for Chanwoo. When a Dom and a Sub engage in a scene, a Sub translates most of the power over to their Dom because they trust them- And this was clearly a breach of trust, because does Chanwoo look okay in those last panels to you? I think not.
And this isn't the only time this had happened- It has happened before, where MD has acted purely on his emotions and thought of himself- Like when he whipped Chanwoo continuously after they'd literally just finished a scene. In a real-life scenario, going into that kind of play immediately after you've already done a scene, would fuck a sub up hard- And require so much after-care it's insane. And that's just not okay, whether you like it or not.
So maybe I don't know much about BDSM, but I do know when a human is uncomfortable- Which Chanwoo clearly was. Do I think Chanwoo was in the right? No. Do I think MD was in the right? No- But there are certain ways you go about things, and this ain't one of them.
I understand what safe words are for, but you can't honestly tell me that Chanwoo looked okay in any of those panels, and that's on MD. I know BDSM is supposed to push you past your limits, supposed to help you break down and be rebuilt again- But there's being broken down in that sense, and then there's genuinely breaking down both mentally and spiritually in the middle of a scene. It was clear that Chanwoo was not okay, and given that MD was his Dom, I guess I expected too much out of a yaoi manga, you know? Like, I expected him to take control and stop the scene, noticing what was happening was genuinely upsetting his sub, or at least use the stop-light system to check up on him- But that was probably just my nativity, hoping for the best in a genre such as this that normally abuses the use of bdsm.
MD is not a very good Dom, and now I kind of hate this side-story. That's a real shame.