A common theme in gay porn is the seduction or “turning” of straight men, especially masculine men in any sort of uniform. Matthew Shepard was no exception. He once continually pestered a hetero guy at a campsite. The guy made it clear he wasn’t interested, but Shepard continued to press him for sex. The guy finally hauled off and punched Shepard, breaking his jaw. This was only revealed several years after his canonization, perhaps in the book cited above.
Water under the bridge. Do you think the truth matters to these people? The rest of the people know about it as much as they know where the Gaza is.
And some women like the idea of turning gay men.