I have another theory..thoda boring hai but we can digest it.
So Chotu Aman ke kisi guy friend is beta hai. Chotu parents died in some accident (may be jinn responsible) and Aman ushe Ghar le Aya! And it's common for kids to call Dad friend chachu..
Now farista Dil is not patent of Roshni only..😉
Aman can be farishta too at times..🙂
This will melt Roshni to the ground. That tree will be so bombarded with new flowers. 😆