I'm perfectly aware that there are people who truly are celibate. However my comment is based on a biography that I read recently, The Last Sorcerer, which identified 2 men who Newton was intimate with over an extended period of time who are suspected to be his lovers. (At least by that author.)

As I admitted in response to adrianh, my impression is that this biographer is fairly highly regarded, but I don't know how widely accepted his beliefs are.