Today for the first time they have slightly revealed Ritwik's evil intentions.
Instead of talking to Sona, he chooses to talk to Bijoy about Dev's phone call and almost indirectly threatens him that he might call of the marriage.
Now I kind of believe the article telling that Ritwik is interested in dowry after marriage.
May be he wants Sona as well as dowry and that's why he refuses to take money from Dev.
http://www.serialxpress.com/upcoming-twist-4159-a
http://www.metromasti.com/tv/gossip/Kuch-Rang-Sonakshi-shattered-once-again-post-Ritviks-betrayal/70901