I honestly want to see if I could tie little flowers to Kaneki's kagune. There are little peeled back scales on them that seem to sometimes perk up like claws, not to mention the insect segments on Centipede's extra sacks, throw on every color I could think of, mindful of its power but trustful of Kaneki's will to never hurt me.
I think in our little world, Kaneki gets to feel a bit safer and more relaxed so he can appreciate the gentle treatment.
In a world like that, I think he'd be flustered but appreciative of the pretty colors and your gentle handling. He doesn't get an opportunity to get dolled up or pampered, so this is very special! Once he knows your intentions are sweet, he'd be a nervous but happy little puddle, squirming and asking "like this?" "Can you reach?" "There? Okay- Tell me if I need to move-"
Centipede may be more skittish and need more breaks, but he would look so cute with little flashes of color all over him!