So basically what I inferred from the conversation between Tina , Sajid and shalin is that,
Sumbul likes someone else and wants to marry him but he isn't giving commitment and then she joined bigg Boss and got drawn towards Sha and has a crush on him but she herself doesn't know she is romantically attracted to him?
I somehow agree with Tina here, that it's not possible if you have crush on someone and you yourself don't know.