I don't think thats the case because Bum was poisoned. If they were switched, he would have been fine.
Sangwoo is more resistant because his mother poisoned him when he was younger.
Maybe he became sick because he believed it to be poison.
I dont think so.
Sangwoo wasnt sick because he has bigger tolerance because his mother was poisoning him.
what chapter is this?
ohh maybe that's why
chapter 4-5
So that's the reason
When yoon bum tried to poison sangwoo, it didn't work because the pills were already switched .(⊙…⊙ )
not sure just a theory please correct me if i'm wrong