Ah, thank you, thank you.

I had realized most of your points, but one I overlooked was that the boys were both raised by merely their mothers.
I hadn't thought of it before I started working on a never-going-to-get-finished-fic a while back. In it, Yusuke is a single dad and gets together with Kurama. I realized one day, "That's interesting—two guys who were raised by single moms and are now raising a son together."

Anyway, I'm glad you enjoyed the essay. ^_^