No one sleeps with entire towns or other such populations because the other people have wills of their own, aren't things. Not every man in the town would want to sleep with that woman or would have the opportunity to do so. Even a sex addict only sleeps with people who are willing to sleep with him or her. There's not enough time, place or "interest" for a single person to do whole populations in a reasonable scenario. Even books and movies have to imply years of time for people to have slept with very many people.