In modern culture we often find closeted gays being the most anti-gay forces in culture. Note for example Paul Pressler in the Southern Baptist Conference.

As to doing 'sodomy' without realizing it, I've heard gays even in recent years saying they were getting sexual as boys without having any idea what it was called. In Calvin's day this this crime is spoken of as if utter monsters were involved, but with no specificity as to how it's done.

So I found it very plausible, as Diarmaid MacCulloch notes, that men would be "bewildered that what they had done could be associated with the crime not to be named among Christians.”

And that would set up a narrative of being punished for "sodomy" & spending a lifetime opposing & concealing it—while seeking emotional relationships with other men. Calvin's puzzling life comes into total clarity.