Then it's upto Upen to question it. Is that tap water or bottled water sonali?Upen grew up in London so tap water is bad for him. It might give him major food poisoning. I grew up outside India but when I go to India I avoid drinking tap water at any cost because it makes me terribly sick.
P.S his immune system is weak compared to people who have grown up in India because they are used to it and their body can handle germs that are in tap water unlike his.