Sam Vaknin is a self-proclaimed expert on narcissistic personality disorder and has written extensively about the topic. It's important to note that his views and claims have been criticized and debated within the mental health community.
Regarding the statement you mentioned, it appears to be a generalization and an extreme characterization of a malignant narcissist's behavior. The term "malignant narcissist" is often used to describe individuals who display narcissistic traits to an extreme and harmful degree, including a lack of empathy, manipulative behavior, and a sense of entitlement.
However, it is crucial to avoid assuming that every individual with narcissistic traits will necessarily engage in harmful or inappropriate sexual behavior. It's essential to differentiate between various aspects of a person's personality and not generalize specific behaviors to all individuals with certain personality traits.
In any case, making sweeping generalizations about any group of people can be misleading and unfair. If you are dealing with someone who exhibits harmful behavior or suspect they may have a personality disorder, it's essential to approach the situation with understanding, compassion, and seek professional help if necessary. Professional mental health providers can provide a more nuanced and accurate understanding of narcissistic personality disorder and its manifestations.