Ovi is Arjun's childhood friend, and claims to love him so much. So how come she even did not think once when he saw Arjun from the side and back hugging Purvi that he could be Arjun. May be it is hard to say for sure because looking from back and side but still one would be able to have some sense that the person I am seeing looks like my boyfriend. I even recognize my friends from their back and sides. When you are so much in love with someone your heart also gives you the sense that he/she is near you.