i know this is kind of hurtful .. but im feeling that in the show..as the episodes keep moving ahead..its going to reveal that arjun does really love gauri but is infatuated in her love...he is only running away from her because he knows he is not a good guy and she deserves someone better and he wants her to marry rajveer for her own good and a better future!!.. and then when gauri is getting married to rajveer he's going to realize then that he never loved her because he's not even a bit hurt of seeing her getting married to someone else instead his eyes are only on arohi and he's going to wonder what's happening to him... then slowly slowly he's going to fall in love with arohi!!
Because if you think about it why would arohi fall in love with a guy..who's bestfreind he's inviting to his house.. making it seem like he wants to mess around with her!! that obviously gives gauri a really bad image of him...she is going to find out that he actually likes gauri but by that time it will be to late to do anything about it and that's when shes going to fall for him as well