He started admiring her, feeling for her..
I just found his unrealised love in that..
And when he said to lakshya that swara is his wife, their intention was to make them believe that they are actually married..
The way Lakshya behaved with Swara that time, by questioning her, and holding her in an authoritative way, that too before the family and in laws was quite embarrassing.
So no fault in reminding him that she is somebody else's wife.