Derek snorted, but he could see that Stiles was greedy for it not because he wanted to be in control, but because he saw it as a judgment on his own skills, thinking that Derek had found him lacking. He hadn't, but that was a lesson for another day. He moved his hand back to curl in his hair and hold his head steady as he let the teenager coax him to completion, chest rumbling with a moan as he spilled down his throat.