I don't think because of any rivalry or competition. I think he loved her as he even now too confess it that she was his first love.
Btw I think sometimes or say most of the time some people because of outer beauty fall or feel attracted without care about inner beauty. If her lenses would be out, she's really beautiful as some days ago I saw a pic of her without lenses. Actually her lenses are main problem.
In bb13, Sidharth the man who never confirmed any of his relationship, in front of Shehnaaz confessed that he had relation with Shefali Jariwala and I can't even say how we fans reacted that time. We were wishing that please Siddy tell you are lying but alas actually he had and then we some days just discussed about what he saw in her that he made her his gf. So sometimes we can't imagine or don't want to accept the reality.
And also in kkb though it was his promised towards his friend but still Purab's marriage was fixed with Aliya, the horrible dakini. I don't know how much you people like Aliya but when I first saw her, I was afraid. She was too dangerous for me. It was Bulbul who saved Purab from dakini, his destruction. But I liked whenever Purab insulted Aliya especially in front of Bulbul and took stand for Bulbul and here too whenever Virat insult Priyanka, I feel pleasure. But there Purab many time disappointed me for not taking stand for Bulbul in many places and here Virat ki baat toh chod hi doo.
So now main point is till now they are showing she was his love, but aab age if they will show his love for her was just infatuation then that's their wish.
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