He feels threatened. There are many ways of being sadistic. A resounding silence is one of them. Often the voice of the narcissist is so well embedded in his victims that he no longer needs to say anything. It is the act of seduction that matters, not the actual physical sex that comes with it.
Somatic narcissists are often infidel and serial lovers.
And this is only in the first three sessions. To show magnanimity is a way of flaunting one's impeccable divine credentials. It is an act of grandiosity. You are not relevant, a mere receptacle of the narcissist's overflowing, self contented infatuation with his False Self. It is transient.