Re: 15th
Derek rolled his eyes, Stiles' usual arguments losing their effectiveness on Derek completely. But he did put Stiles down this time, though he stayed close to make sure Stiles did have something up his wholly metaphorical sleeve. "You thrashed around when I had a razor near your balls. That one's on you. And I'm not done."
With a slightly too-firm hand on Stiles' elbow, Derek started to tug him towards the tub again. "Get in. On your knees, facing this way." Derek pointed at the side opposite the tap; Stiles was right, in a way. Derek had nicked his skin and there was one simple way to prevent that from happening again.