Why? Because the kinds of sex that don't involve male/female genital copulation scare a lot of conservative straight people, and when they picture any other kind of sex (which of course in their minds' eye they probably do visualise if they can figure out the positions), it scares the bejesus out of them. Could be they're afraid it could happen to them (or maybe they're afraid they'd like it. . . )

Condemning "forbidden fruit" is not an uncommon pastime for those who announce to the world that they are in posession of a patch of moral high ground. But it's an illusion, and the courts and the laws are slow to come around to recognizing that the playing field should be level.

Forbidden Fruit a flavor has
That lawful Orchards mocks --
How luscious lies within the Pod
The Pea that Duty locks

-----------Emily Dickenson