Sexism occurs when we assume that some people are less valid or natural than others because of their sex, gender, or sexuality; it occurs when we project our own expectations and assumptions about sex, gender, and sexuality onto other people, and police their behaviors accordingly; it occurs when we reduce another person to their sex, gender, or sexuality rather than seeing them as a whole, legitimate person. That is sexism. And a person is a legitimate feminist when they have made a commitment to challenging sexist double standards wherever and whenever they arise. An individual's personal style, mannerisms, identity, consensual sexual partners, and live choices simply shouldn't factor into it.
Julia Serano, Excluded: Making Feminist and Queer Movements More Inclusive
feminism, feminist, sexism