Pakistan doesn't have to choose sides. Example: When 2 out of 3 brothers don't like each other, the 3rd brother doesn't choose sides. He knocks some sense into them and if they still don't listen then the 3rd brother resumes the knocking of sense. The Iran/Saudi rivalry is childish and just plain stupid.
Iran, Pakistan, & Turkey are the only 3 countries in the region that have advanced R&D in the military field. It is vital for the Muslim World for these 3 to form some type of alliance. The Arabs have economic power and most of the trade will come from here to CPEC.
If Iran & Saudi can trade with Pakistan & India then so can we. If Iran & Saudi can't give an explanation first, then they have no right asking Pakistan for an explanation. It is not Pakistan's fault Iran & Saudi are desperate for Pakistan's attention.
Pakistan will continue to treat both wives equally.