As per appearances, Mamaji is of a somewhat smaller frame... and unless we want Arnav doing a 'Desi Boyz' gigolo with skin-tight shirt act, he is better off with the rainbow colors of his new and improved wardrobe.
What am I saying! Duh!
I am all for Arnav wearing Mamaji's clothes! Bring it on... I've got all the $1 bills to stuff in... er his pants waist.