There are the three ways to tell if you are dating a high conflict, toxic person. Usually these type of partners are extremely charming when you first meet them. There is also an element of fake compatibility in the relationship. What that means is that they will change themselves in order to be more compatible with you. They are also know to have extreme sexualities. According to business insider, "It is common for narcissists to be sex addicts or at least claim to be."