Sitles took Derek's cock, keeping his jaw and throat relaxed so he could, until he let out a whine when Derek told him he was going to cum on his face. Stiles let out a disappointed noise when Derek pulled back because he had wanted to taste the werewolf.
So when Derek came all over Stiles, strings of come hitting the human's face, Stiles opened his mouth and stuck out his tongue to try and catch some.
"Master..." Stiles panted softly, completely turned on and unable to come because Derek hadn't said he could.