Haven't watched the episode yet so can't give a definitive answer but from what I know so far, I will agree with Anu.
Twinkle constantly throwing the rape accusation into Kunj (which in her perspective is fine since she actually believes he did the act); is a way of her telling Kunj that THIS is what I think of you and how much I despise you. I don't want you anywhere near me and because of what you did, I no longer trust you and I will doubt everything that you do from here on out.
Same thing with Kunj. He is getting so tired from being accused that he is lashing out in his way. He will never hurt her physically, but with his words, sure. Him giving that statement is, like Anyu said, his way of telling her that he is not sexually interested her now and with the way she's acting, never will be.
I.e., they both don't want to be physically near each other than what is necessary and there is no way that their relationship will ever love forward to being one of an actual husband and wife's. They are in this relationship only for their families and they will be linked to each other only legally and on paper. There will never be any type of intimacy.