(Before reading out reasons do keep Ovi's & Purvi's mistake aside as rite now v r talking of Arjun as an individual)
1. If a guy knows dat he already got physically intimated wid another gal ( his fiance) n still he agrees to get married to someone else jus for sake of tyaag n balidaan which her gf was making. Purvi was acting stupid but why did Arjun gave up to her demands.
2. Chalo shaadi ho gayi out of emotional blackmail n all but why did Arjun consummated his marriage n dat too not out of love but again coz his gf asked her to do so.
3.cool consummation happened...after dat Arjun was supposed to b physically n emotionally be wid his wife...emotionally he was never wid his wife.
4.After knowing Pari's truth why didnt Arjun conveyed it to Ovi n Family asap...he stopped n postponed it as Purvi asked her to wait for sometime.
& d weirdest part Arjun started loving pari more after getting to know dat she is purvi's child & not cried even once for his own baby
SO YES ARJUN DID BETRAYED OVI BY NOT USING HIS OWN MIND & ALWAYS GIVING UP TO PURVI'S USELESS DEMANDS. A MAN WHO KNEW THAT HE WILL NEVER B ABLE TO GET OVER HIS FIRST LOVE WHY DID HE GOT MARRIED.