Bruhhh... Wtf is ibrahim thinking?? I know he's very loyal to the king, but Mustafa inheriting the throne means the other brothers will be killed, because gulbahar will be empress dowager.
I understand not wanting his (??) child to be the sultan (ultimate betrayal to his king), but to the extent that he's willing to accept his kid and hurrem (his ex-lover) probably dying? There's no way gulbahar will let hurrem off after all the humiliation she felt.
He always had the option of pushing selim (3rd son) to be king, if he's that desperate for suleiman blood to inherit the throne.