It's fine! [He grins and flexes it in demonstration, flips it palm up to examine just what changed to make this effect.] I turned off the pain receptors while changing it, but they're on again and nothing hurts. What do you think, does it look like yours?

[Belatedly, he remembers the whole reason Sans went intangible in the first place. Processing power for parallel trains of thought is no guarantee he'll keep actively thinking about things, sometimes... The amused and self-satisfied grin fades to something more forced, but doesn't fade entirely.]