Coming back to my "ace & sex-indifferent but down to clown" Shadow HC : Shadow & Sonic getting intimate very often, but with a major focus on Sonic.
Like, Shadow is more than happy to use his claws and (freakishly long) tongue on him, but has zero interest in using his dick or getting an orgasm of his own.
It's a "service top & pillow princess" dynamic taken to the extreme, to the point Sonic's never actually seen Shadow's genitals.
Sonic feels a little guilty that he's the only one to get his rocks off meanwhile Shadow is completely unbothered like "Do you really think I would be doing this repeatedly if I didn't like it? Fool. You absolute moron. You complete idiot. Now get back here so I can shove my tongue in you."
I like the idea of those two having unusual sex because of Shadow's own unique relationship to sex.
It's also partially projecting because as an ace person I am deeply unsatisfied with how people like to portray us engaging (or not) with sex. It's usually some insulting form of "ace people hate sex" or "ace people are innocent babies who know nothing about sex". Usually more the second one if autism is also involved. 🙃
Idk sorry for the unexpected rant. I just have Feelings™ about sex despite (or maybe because) of my own equal indifference yet fascination for it.
Anyway, fandom peeps should headcanon their blorbos as having unusual sex more often, methinks. Regardless of the whole ace stereotyping...it's also just fun.