This manhwa's comments reminds me of something someone said. Yes male leads can be rapist, abusers and murderers but God forbid that they cheat. Cheaters are the worse.
Or something similar to that tune and it is true. You can have many people argue that a manhwa is fiction so when male leads rape, assult, abuse, confine and kill the protagonist family and friends and many innocent people it isn't a big deal to get upset about but if the protagonist or male lead cheats... then that is the absolute worse. And somehow people actually care for characters who aren't the main character now.
This givea me the feeling that the author didn't really know how to continue the story so wanted to add something in to extend it