ok i saw the epi now i think:
Dutta semed to be angry and lost in his thought and the pain i saw in his face semed to be like "why didnt u tell me before" i actaully think that he is upset that nakku didnt trust him enough to tell him that she loves him..he is angry that she did not open her hearth to him in the first place instead of going this way.hmm ab mere opar jootey mat phenkna but i really think so..!😆
yes thats what finally set him off. she loved him and STILL had to betray him? like he told supriya's father...dhoka dena zaroori tha. there were other things ofcourse in his head and thats why that intense reaction.