Derek's mouth thinned into a tight line at Stiles' admission. He'd wanted to assume the best of Stiles, that the boy with him had been nothing more than another slave being helpful. Apparently his initial impulse had been right, if the boy was sore and testing his...flexibility.
"Why are you calling me Mr. Hale?" he demanded, clipped. "And you never answered me--why do you have Joseph and Amy's clothes?"