"Yes, sir," Stiles breath out, keeping himself spread for Derek anyways, as he watched the werewolf tense up and then start to come. Stiles was to tired to move when the first warm splash hit his chest and when Derek started to hit his cheek, mouth, nose, Stiles wanted to look away to protect his eyes but he didn't. He did close them just in time, feel come splash against his eye lid, and when Derek slumped forward Stiles opened them back up.
He looked up at Derek, his breath slowing down now, as his tongue flicked out and taste the come that had landed on his lips.