Biphobia

Biphobia or monosexism is aversion toward bisexual people or bisexuality as a sexual orientation. Biphobic prejudice commonly presents as denial that bisexuality is a genuine sexual orientation, negative stereotypes about people who are bisexual (such as the beliefs that they are promiscuous or dishonest), or bisexual erasure.

The hatred of bisexual women is referred to as bimisogyny or less commonly bisexism.