Ovi can't be blamed. Ovi agreed to hide the truth of Onir from Purvi-Arjun after Onir requested her to do so. It is Arjun this time who wants to reveal the truth about Onir to Purvi. In yesterday's episode, Arjun saw the picture of Onir-Shalini fake marriage in Ovi's room in hotel & Arjun forces Ovi to tell the truth. Ovi was trying to hide it, but Arjun compelled her to tell the truth about Onir. Ovi infact tried to stop Arjun from telling the truth to Purvi saying that she has realised that Purvi loves Arjun only & not Onir. But, Arjun did not listen to her & is just ready to tell the truth. So, Ovi is never responsible , but Arjun is responsible.