Hey it could be that Angad spoils Sur so he makes sure that she loves him and that she'll never leave him. Maybe he thinks that when Sur finds out that her mother is Kripa, that she'll go to her and stay with her so hes spoiling her so she likes agnad better. i think hes scared that Sur might leave angad and run away one day just like kripa did.
OR
If Sur ever finds out this isnt angads Real daughter and wants to go to her real father, she'd like angad better because he gives her everything she wants.
What do u think? Sorry if i'm confusing you😊