According to Everyday Feminism's transgender feminist Riley J. Dennis, if you have a "genital preference" and are not sexually attracted to both a penis and vagina, you are transphobic; or, as he interchangeably uses, "cissexist."
In a video posted last week, Riley argues that "genital preference" is actually a form of discrimination against trans people. For instance, if you "identity" as a straight male but have a preference for women without penises (because in Leftist Land some "women" have penises), you're transphobic.
"Gender" preferences are allowed, so long as gender is defined by the Left's Baskin-Robbins-esque Gender Chart, where feelings supersede biology.