I mean to be flexible enough for that not to hurt your back even slightly, you’ve gotta be a very competent gymnast or have some sort of disorder/bodily abnormality. I considered myself pretty flexible right up through my early twenties (enough to be able to put my feet behind my head, which I can still almost achieve! Almost. Think I can only manage one at a time now, barely, haven’t tried in ages), and that shit was still so painful it managed to negate all the joy of a blowjob.

But for a masochistic gay narcissist, it would tick all the boxes.