A Narcissist is a person who will present themselves as a most helpful, caring, charming, agreeable, generous, and adoring person who is very much wanting to be your partner in life, married or not.  Those who fall for these predators will always suffer at their hands and depending on the individual needs of that particular narcissist the abuse can be on a scale from unacceptable behaviours to outright nightmarish verbal and sometimes physical abuse if a covert narcissist knows you are about to expose who they really are behind closed doors. The damage these predators are capable of inflicting is criminal and yet they are seldom made to face any consequences because they are usually highly intelligent and know how to lie really convincingly and play the victim better than the real victim. 

Many who end up in partner relationships were raised by narcissistic parents (one or both), had siblings or other close relatives who were narcissists, and are the exact target preferences for narcissists because these persons are usually very much "people pleaders" with unstable boundaries in personal relationships and want very much to be loved and valued. After becoming their partner, a narcissist will proclaim how much they love you while blaming and devaluing you for everything you do while they do whatever they want to do and you are not going to be allowed an opinion or a question about their actions and behaviours without negative consequences in one form/degree or another. 

I am in recovery from narcissistic abuse and doing so very much better emotionally but it did not happen overnight as I had two years of intensive counselling therapy so far and I have done so much homework myself to understand who, what, where, when, why, and how all of this came about in my life. Most importantly is the discovery that I had a self-love deficit and I wanted someone else to fill that void and this is the biggest reason that I attracted narcissists into my life. They can sense this need in a person like a bloodhound can scent a rabbit.