Abnormal is a completely unscientific and immoral word to use in the context of consentual sexual behaviors for it is factually wrong (see the distribution of homosexual or bisexual behaviors in mammal species including humans), and also invoking a moral presciptive by declaration "what should be normal" via telling other people what "is not normal".

You fall into the same trap ("non-standard", "atypical"); you just stepped on the euphemism treadmill.