Being gay is a fetish.

[Esquilax]

First lets define natural.  There are two ways it is used in this debate.  The pro gay crowd defines natural as "occurs in nature".  The anti-gay crowd defines natural as "the usual and ordinary course of nature".  Very different meanings and each is equally valid.

It's starting to get laughable now: under both definitions, homosexuality is natural. It occurs over multiple species fairly commonly, making it usual, and given its unremarkable nature, it's also ordinary.

The only thing Heywood has left is to redefine "usual" and "ordinary" too, and at that point he's just playing word games and then demanding everyone else reimagine English to be whatever he wants.