In order to understand what Sid is going through I feel one needs to be in his position. His mind is not where it used to be. When Roshni was with him, he was able to handle everything but now he feels as if his whole life is falling apart. He is in a vulnerable state now, mentally & that is when people are easily manipulated. When you lose someone you truly love you are unable to think straight. As for Sid he feels lost & confused. I don't think he is being dumb. I truly feel bad for him. He can fix everything if Roshni is with him.
I sympathize with Sid but after a point, showing him getting fooled and not using his brain is just reducing the charm of the show😕 I want CVs not to butcher Sid's character more