Dude, they couldn't ever do that though? It's an extremely unconventional relationship, and the only reason they found their 'love' was through being put in these situations. Bum has finally been broken by Sangwoo, which I think is what he wanted, so they couldn't just "leave everything". You can't really live a normal life after doing something like what they've done.
People do bad stuff but think they can't stop from doing it cuz that's the only thing they can do and don't realize that they can stop and change. A boy who has lost his parents and then been rapedal and abused is not only broken but also angry...those people need to to change their life and try to move on. OK killing is not something you can forget, but as a watcher thats the only think I can wish. The thing is, I always try to understand even the baddest character.
Even so, what they've done is illegal.
Do you think it's even fair for them to just 'change their ways' when they've taken a life? The girl they killed in this chapter probably has a family, and we know her to have a lot of friends. Someone will notice she's missing. If Sangwoo and Yoonbum left the situation now so suddenly, it'd cause suspicion.
But hey, don't get me wrong. I love these characters, even though they're messed up, so of course I want what's best for them. But I also think they'll reap what they sow, soon.
From stalkIng to killing. I just hope they would sell the house and move to another city so they can live a normal life. But they don't want a normal life. They want to punish random people for the sins of another. They should just leave everything behind and stop before getting caught.