An emotional affair is the "perfect romance" for many people. Generally it happens between two people who are not in physical contact. They pour their hearts out, express their feelings and dreams about everything in life. They reveal things to one another they have never told anyone else including their mate, spouse, or significant other. After a while they come to feel this (secret friend) is the only person on earth who "gets them". He or she is accepting of all of their flaws and always encourages them to be themself as well as supports them with any goal they want to pursue. They never fight or disagree with one another. What makes it all the more intensely "romantic" is having something that keeps them from being together in the physical realm. It's usually distance, commitments to other relationships, or having children to raise...etc They speculate, how could life had been so crule to allow them to find their "soulmate" AFTER they had chosen another path.
Having a hypothetical or "emotional relationship" never deals with the day to day realities of taking out the trash, doing laundry, paying bills, cleaning the house, cutting the grass, dealing with their friends/family, or seeing things you dislike. You fantasize that if you could be together everything would be "perfect". There is no such thing!
It goes from being emotional when it becomes physical. This is generally when you find out if both people are ready to make their (emotional affair) a real relationship by coming out to the world. Usually one person starts to backtrack and things begin to unravel. Very rarely does any type of affair lead to a fairytale ending.