Why do men in Mumbai hotels have two wives?

Plot introduction:

The story happened in the Taj Mahal Hotel in 2008, and a group of bad guys surrounded it in Mumbai, India. Among the dedicated hotel employees, the famous chef Hemmant Oberoi and the waiter Arjun (Dev Patel) choose to risk their lives to protect their guests. With the whole world watching, a desperate couple was forced to make unimaginable sacrifices to protect their newborn baby.

Role introduction:

Arjun:

Actor: Dev Patel.

A poor Sikh, with a poor mother and a pregnant wife, works as a waiter in a hotel restaurant. He was late for work, and was reprimanded by his leader, hotel director Hermet Oberoi, as soon as he arrived, but he could still go to work that day. Arjun risked his life to protect his guests after the terrorist attack on the hotel.

David:

Actor: armie hammer.

A famous American architect and his wife stayed at the Taj Mahal Hotel. They planned their next date in the hotel restaurant, but the short date was broken by terrorists who later entered the hotel. In order to protect the nanny and children in the cupboard from being found, caught by terrorists and killed by his wife.

Sarah:

Actor: Nazarene Boniadi.

An Iranian beauty, Muslim, wife of David, mother of a child, was attacked by terrorists in a hotel, and was arrested after coming out of a VIP bar with a group of people, because the terrorists didn't kill her because of her religious beliefs.