Madhu didnt turn coz of his betrayal.. The betrayal happened almost 2 months back and she was trying to move on with whatever was left of her broken self. It is rk who is not letting her to even move on. If he was just crossing her way every now and then, it was still tolerable; but he is treating her like a puppet. He doesnt even realised his sin (it was not a mistake), and he wants madhu to b wat he wants, do wat he says. She is not his slave. He needs to be told off. But our RK doesnt understand words, so i hope madhus actions does that work