Well, they are not even engaged yet...far far from the mandap. Now i do not know what the creatives have in mind, but at this time it is ok fro Arjun to fall in love with Purvi.i agree,but wen will arjun tell ovi about this,on their marriage manadap,the way armaan did with shravani.
the future story will be purvi-arjun falling in love,purvi trying to sacrifice her luv cause of archana,on arjun-ovi marriage day,archana coming in front and stopping their marriage.