Sexual stereotyping is a form of sexual harassment whereby people label or treat you based on your perceived sexuality. For example, calling a girl a "slut" is a form of sexual stereotyping, and hence sexual harassment. SLUT! by Leora Tanenbaum is an excellent account of what constitutes and what the repercussions are of sexual stereotyping.
Stories from ’sluts’ are interwoven with a narrative on how a slut represents soiled femininity; that is, she didn’t fit in with the gender role that was assigned to her. She also explains why sexual stereotyping can never be justified in any situation, and also explains how it can foster a "culture of entitlement" among males, thus also affecting the male gender.
A good book to read on the issue.