"Oh," Stiles said softly because he hadn't expected Derek to actual kiss his hand. He had been about to back peddle so hard that Derek would have told him to shut up. He had already been rejected by Derek once. Stiles really didn't need it a second time.
"You just told me to get Batman to kiss it better and since he licks his own butt I don't think his mouth is clean." There. Make it light and a joke though Stiles was blushing hard.