Heard this story thirdhand 45+ years ago, but it still resonates with me.
I was attending Sweet Briar College, just 15 miles from Lynchburg in the late 70's. We all heard about Jerry Falwell and how he called us the "Harlots on the Hill" and other weird stuff.
I took a course on Judaism at the college with a Lynchburg rabbi. He told us a story about Jerry that one of his congregants told him. The congregant was likely the only urologist in the city. And Jerry was one of his patients.
One day, Jerry showed up for his appointment. While the doctor was "probing," he casually inquired, "Jerry, what do you call a man who loves another man?" Falwell's eyes lit up like Christmas tree lights, and he exclaimed, "Why, a homosexual of course!"
The doctor kept probing, literally and figuratively. "Gee, Jerry," he intoned, "I was always told when I was growing up that it was a Christian." And Jerry shut up tight like a clam after that. Dead air time.
The op says it took place in the late 70s, and Jerry Jr would have been a teenager then. (magine growing up with Jerry Falwell Sr.. as a father. *shudder* )
The irony is that what Jr did wouldn't be a big deal if he wasn't who he is. Getting off by watching your partner have sex with someone else is a relatively harmless kink (assuming the partner and the other party are all in on it, of course). But because it was antithetical to the views he espoused and the rules Liberty U students were required to follow, it was a huge scandal!
Whatever one may think about sexual kinks, Jr's real sin was his hypocrisy.
Use it to shut up faux christians, either the story or directly. "You do know what a man who loves another man is called, right?"
Doesn't matter if the story is true or not, the punchline sure is. Can be anybody else in the story, like Mad Maga Mike.