DOnt know whetr aarti tell yash the truth or not but...if she tells he will be angry for sure...but i think yash will surely try to reunite prashant and aarti...
but yash will not be impressd by the way prashant treat aarti and ansh...and ask him to go away from aarti and will tell him that he wants aarti as his wife and as his daugters mother...also wants ansh as his son...then prashant will b revengeful or his part will get over
then arpita death is not mentiond till now in the serial...but iam sure that she is not alive...if she is alive no one can unite yash and aart...if arita's was an accident type death i think aarti will also come across the same situation wich reminds yash of arpita's death and will save aarti for he dont want to lose her