Why Rishabh's face so tight when Salman jokes with him

I don't understand why his face becomes so tight and expressionless when Salman jokingly points out at him.
Is he overawed by Salman and misunderstands him that he is bashing/scolding him.
Or he doesn't have common sense of laughing off at a joke harder when it is on yourself specially from someone like Salman.
Reminds me a bit of Karishma Tanna, she used to get scared in front of Salman and used to take his jokes at heart.

Everytym I watch Rishabh on WKW, I am like y is he so unkempt?? He has so much hair tat I am not able to see his expressions😆😆😆 Pls bhai thode baal Prince aur Salman ko de do 😆

I have the same question 😕