I'm thinking back to all the wedding rings (or obvious wedding-ring indentations) I've seen on men's fingers while they cruised gay backrooms and other (less safe) meeting spots.
(Back before legal same-sex marriage, some gay men in committed same-sex relationships wore wedding rings, but not very many, at least in my experience.)
One of my more popular stories quite a few years ago was about meeting a "straight" Russian immigrant on the beach who was eager for an illicit hookup with my speedo-clad, stereotypically gay self. I didn't care about his wedding ring, but I absently fingered it while engaged in a moment of intimacy, which prompted him to ask if I was married too. He seemed disappointed when I told him no.
He was evidently part of that shadow world you describe, a quite large world, I think, made up of bisexual men and closeted gay men who present as straight.
It's really nice to see how many men are coming out of the shadows these days. Thanks for this story about your journey!