I just remembered a 3rd faerie lover rule

28. Faerie lovers tend to be quick to become jealous so don't cheat on them. It will likely end badly either for you or the person your cheating with or both. You would need to make sure to end the relationship with the faerie first which is simple enough. Usually asking them to leave is all it takes but if they are persistent then you might want to seek help from an exorcist or something to that effect.