I’ve had a head canon for a while that Shiro dislikes having his scars touched. Not just for hating how his body looks and trauma reasons, but also because many of his scars are numb and dips into/under the rest of the skin. When he knows someone is touching one and he can’t feel it or see it, he starts getting disturbing thoughts, like what if they’re touching the bone beneath or pulling it open again. It’s not about trusting the other person, but not trusting the soundness of his own body.
I’d really like to see a porn/body worship fic, where Keith has to work around this while still convincing Shiro he finds him attractive.