I dont think he is playing with anyone's emotions or cheating or anything derogatory. He is hurting a lot too, he wants to be with Purvi but he will hurt Ovi deeply, especially as she is consistently professing her love to him and even sacrificing her career. It was clearly not his intention to hurt either of the girls, he had no idea that the engagement was taking place...that is not something thta should be sprung on a 'couple' it should be their decision alone. His emotions were not so invested in love and marriage pre-Purvi...he just seem to be going through the motions with Ovi, as he was a workaholic.
I really do feel very sorry for Arjun as much as Purvi and eventually Ovi.
I also think Arjun/Purvi should be put on hold until Archana-Manav misunderstandings from a long time ago are cleared...otherwise this Ovi/Purvi/Arjun triangle will cause even bigger problems for Manav and Archana and divide the family further, as only Archana might support Purvi. Cant see Tej, or manav not supporting Ovi
Please give the guy a break, he has feelings too