Dear fellow classmates,
Asexuality does not necessarily mean that a person is disgusted by intercourse
Asexuality does not mean that a person is an emotionless, hormone-less robot
Asexuality does not entail total disgust concerning sexual acts
And Asexuality is not merely a phase that people go through when they are too young to understand what sex is, and are thus repelled by it.
So please make sure you understand a concept before making arguments against it.