monosexism

Etymology

From mono- + sexism.

Why this word is great

MONOSEXISM — [Noun] The assumption that everyone is monosexual (i.e., attracted to only one sex); the belief or assertion that bisexuality and pansexuality do not exist. From mono- ("single, one") + sexism ("discrimination or prejudice based on sex"). Unlike "biphobia" (which targets bisexual individuals with fear or disdain) or "heteronormativity" (which enforces straightness as default), monosexism is the structural denial of attraction beyond binary exclusivity—whether gay or straight. It is the raised eyebrow at a bi woman dating a man ("just a phase"), the insistence that pansexuality is "greedy," or the casual erasure of multisexual histories in textbooks—a quiet violence that insists the world must be simpler than it is.

noun

The assumption that everyone is monosexual (i.e., attracted to only one sex); the belief or assertion that bisexuality and pansexuality do not exist.“Oppression of bisexual people is based in part on heterosexism and in part on monosexism, the belief that people can or should be attracted to only one sex/gender and that there is something wrong with those who cannot or will not choose.”