Sentence:  “Ours is a sexualist society,” Evan began. “In particular, we have come to believe in constraints on the love which can exist between women and women, and men and men. Unlike other cultures and other times, we have made the gender of our beloved, and not the quality of the love, the overriding issue. This <WSD>sexualism</WSD> is pervasive and insidious.” 
Meaning of the word marked with <WSD> tags:  The belief that one set of sexual behaviors is intrinsically superior to another set of sexual behaviors, or prejudice and discrimination based on that belief.