Why does the Narcissist devalue his source of Secondary Narcissistic Supply?
Narcissists are forever in pursuit of narcissistic supply. They are not aware of past or future, are not constrained by any behavioural consistency, “rules” of conduct or moral considerations. Signal to a narcissist that you are a willing source – and he is bound to extract his supply from you. This is a reflex. He would have reacted absolutely the same to any other source. If what is needed to obtain supply from you is intimations of intimacy – he will employ them liberally.
Some sources of supply are ideal (from the Narcissist’s point of view). The ideal source of supply is sufficiently intelligent, sufficiently gullible, submissive, reasonably (but not overly) inferior to the narcissist, in possession of a good memory (with which to regulate the flow of narcissistic supply), is available but not imposing, not explicitly or overtly manipulative, interchangeable (not indispensable), not demanding (a fatalist to a degree), attractive (if the narcissist is somatic). In short: a Galathea-Pygmallion type.
But then, often suddenly and inexplicably, it is all over. The Narcissist is cold, uninterested and remote.
ONE of the reasons is, as Groucho Marx put it, that the narcissist wouldn’t like to belong to a club which will accept him as a member. The Narcissist devalues his sources of supply for the very qualities that made them such sources in the first place: their gullibility, their submissiveness, their (intellectual or physical) inferiority.
But there are many other reasons. For instance, the narcissist resents his dependence and by devaluing the object of dependence (his spouse, his employer, his colleague, his friend) he gets rid of the dissonance.
Yet another issue:
sex and intimacy are usually also connected to past unresolved conflicts with important primary objects (parents or caregivers). They invoke these conflicts, encourage transference and provoke the onset of an approach-avoidance cycle.
Additionally, narcissists get tired of their sources. There is no mathematical formula, which governs this. It depends on numerous variables. Usually, the relationship lasts until the narcissist “gets used” to the source and its stimulating effects wear off OR until a better source of supply becomes available.