It is correct that Onir must divorce Purvi first. Now he is so busy putting up the act and sdoing ridiculous things like pretend wedding etc. He himself seems to have forgotten that there is a legal issue for him to sort out. However, if he sends Purvi divorce papers she'll begin to question why since she believe her marriage is voided since Shalini is supposed to be Onir's wife. This will raise suspicions and the lie will out. So Onir Babu keeps quiet. He's in a catch twenty two and so is the story line. Let's see the CVs crawl out of this rabbit hole.