In my opinion he made the right decision. I mean if he got married to her and brought her into his house, what would happen if she turned into Natasha when he wasn't there. She's proves to be a major harm to his family. I really really respect his decision. I mean he is emotional torn, but he didn't lose it, he thought it through and he did what he felt right!
I would have done the same thing. And also Kanya hasn't proved his love for him yet, if she had, then maybe I would have felt bad for her. If a guy left his loving family for me, I would mad at him, for making that decision.