Sorbis/ShutterstockSheri Meyers calls it an "affair of the heart," or "emotional sex." You're hardly renting a hotel room together — at least not yet — but you're going out to lunch every weekday and trading intimacies, and when you get home at night, you can't stop thinking about them. Or, maybe you haven't met in person, but you chat online for hours at a time. Emotional affairs are hard to define exactly.