It also serves as a way of discounting any future comments the other person use to embarrass the narcissist.
Basically, they are beating the other person to the first punch.
Even this definition is slightly incomplete; AVEN implicitly indicates asexuality only refers to lack of sexual attraction to another person.
(1) The reason I cite a non-academic website (AVEN is actually an online community for asexuals devoted to providing opportunities for these previously isolated individuals to interact and promote awareness about asexuality) and put "experts" in quotes is that the subject of human asexuality has received almost no academic attention, nor in literature, nor by society, and only in the past few months has it become a hot topic in the media.
This period of presumed purity worked fairly well for asexuals, especially for those seeking a romantic partner, since even women were (sometimes) socially permitted to refuse their husband's requests for sex.
However, any sexual activities or preferences deemed "unnatural" were stiffly condemned (in England homosexuality was punishable by hanging, imprisonment, or as in Oscar Wilde's case years of hard labor), so any individuals fitting the definition of asexual would not try to bring attention to their "problem." In the time between the introduction of liberal views on sex in the 60s to modern day the world seems obsessed with sex.
What is it, and is it really a sexual orientation, determined before birth like heterosexuality or homosexuality are now theorized to be?
The idea is that asexuals may still experience physical arousal but perhaps their brains somehow do not connect it to the act of sex.
In order to avoid a first punch, a person needs to understand what it looks like.
Here are eleven ways a narcissist uses shame to control others.
There are some who are thoroughly repulsed by sex (having it, watching it in a movie, thinking about it, even mention of it), while there are also individuals who just find it unappealing or boring (like washing dishes—if it has to be done you put up with it, but it's something you'd rather not spend your time doing).
There are those who have no interest in dating or forming anything beyond friendship, while some asexuals date, fall in love, and even marry.