Sexual narcissists often exhibit compulsive behavior around sex, which can include unsafe sex and compulsive porn usage that interferes with their lives, says Neidich. "Sexual narcissists are often obsessed with their bedroom 'conquests' and are more interested in quantity over quality," says Santan. Sexual narcissists' compulsions can also include serial infidelity. A 2014 study in the Archives of Sexual Behavior found sexual narcissists are more likely to cheat in marriage. And they'll often cheat without remorse, Neidich adds: "Within a relationship, this will also typically involve blaming the partner, as narcissists are incapable of taking responsibility for their behavior."Sexual narcissists use sex to gain approval, so they may behave charmingly, romantically, and even seemingly generously in order to gain praise and admiration, says Santan.