sorry for the delay i haven't been having much free time!! i'm compiling all the scenarios you sent into this reply!

"Sidetrack but this part reminds me too of a fic from another fandom where he was a corn streamer and the other a follower who gave him big tips and start talking and puts shows for him only and the other stalked him from bf starting streaming and even after they start dating, or another fic where the bttm fakes his identity with the guy he met while playing a game but catches feelings and they start dating and feels bad but doesn't know the guy already knew+stalked him after knowing!
But back to it, maybe another scenario where he also does the jealousy thing I mentioned of having sex or flirting with others knowingly. Either way, simultaneously starts stalking him back with the other thinking it's another person or that he is doing another thing bc he doesn't have cameras nor hacked him. And maybe Hj tells him if he gets bored🙂‍↕️
3. It starts with them stalking the same person(maybe Yh, Ys or Mg!) and notice eo on the same place and from then on they always fight but end up being attracted to eo, hook up and forget abt their victim. But it could also end with the original stalked person finding out and turns out to be a sadist/discovers he is one with them or does it only that time to punish, either joining them and topping both or/and mctz still only fighting and tells them to fuck instead of suing them, or fakes wanting a trio and only the two end up fcking while he watches and end up telling them what do. And masochists mctz are born! Tho Sh sadist side as well with Hj.
Unless only M Hj and both S. Or not SM involved (actually don't usually like it or much unless only psychological depending on context!) but yes D/s :) And the two, three or even more members joining start having lot of sex doing many different things! ^^ One stalks another while the other him and they end up together. Maybe also throwing out there more toxicness with murder or attempted murder out of jealousy and hate to the stalked oor the stalker he stalked and if he lives they still go back together and they live happyly or toxically as a couple after that.
5. Last and my favorite! Hwc stalks Jccng (here could be much less and not that crazy, kinda innocent) but Hj finds or bc of Hwc confessing he did, and Jccng notices or/and confesses sh is the same person he stalked a few years back when they were on the same university! And maybe they were friends that separated naturally or bc of Hj feeling guilty, or just having directly interacted a few times and both or only Hj having a secret crush. And now reunited through work or living close. So they end up a happy couple! 🙂‍↕️"