Engagement night he admired aarti as a loving mother when he saw her playing with ansh in her. he believed that she was best choice for her daughters. he got married just to get a mother for his kids.
Then after the divorce issue, he brought her back home as scindya bahu
But has never declared as his wife. This time as the arpita issue is takilng the stage he will give aarti her identity as his wife on 25th june.
Loop will get closed by this bcoz aarti got married to yas on her same wedding date of hers with prashant.
We all know that yash takes long time to react but when he is into the situation he will put his heart to come out wit a solution. But to get into the matter someone has to force otherwise he will stay happy in arpita's world without any knowledge of knowing wat ugly things happening in his family.
Example gayathri locking ansh makes him realise that his mother n kids have not accepted ansh . so he changed the school which turned out to be good one
and aarti forcing him in ansh kidnapping fiasco , he stood against his father to his duty
similsrly aarti taking arpita's identity also makes him take bold but good decision.