Oof I was sort of zeroing in something like this too but I didn’t way to say anything because I take it seriously. Seoin has a drug addiction and is hypersexual. I don’t remember where I saw it but I think drug withdrawals can also cause hypersexuality I am not too sure because it’s been a while since I’ve seen it.
You aren't wrong at all. Hedonistic tendencies such as sex addiction and drug abuse often go hand in hand. They feed off each other and for example when seo in starts having drug withdrawals he just gets super horny. We see it in the early chapters already.
Yes, it’s definitely a pattern I’ve noticed too. He reminds me of Ian from Wet Sand who also displays hypersexual tendencies and has a history with drug abuse. This is where I’ve sort of built an understanding of it lol
I have a theory on why SEO in has such a fucked up relationship with sex. Like it's not normal that his default setting when it comes to sex is just sadism especially now that we have a backstory. Considering how the nasty ass step bro is obsessed with seo ins attention even if negatively I would not be shocked if he sexually assaulted him by for forcing himself on him. We see it with disgusting kiss and his insistence to brand himself onto seo in so to me it's not out of the realm of possibility. Also seo in possibly being a sex addict is also a sign cz sometimes victims tend to become hypersexual after sexual assault.
Just so you know I'm not dismissing what we already know that seo ins taste of punishment is because of the desire to hurt yw because yw hurt him with the whole ghosting thing. I don't justify that at all. I'm just adding my own other takes.