His arm was dead, in an early morning haze he forgot Cas was in bed with him and quickly yank his arm towards him. This coincidently sent Cas flying out the bed and face plant the floor.
This woke Dean up. All Cas did was moan and groan on the floor.( Cas was not a morning person. Dean found this out the hard way when he woke Cas up at 6am and promptly received at fist to the nuts for doing so.)
"Shit sorry Cas, here let me help"
"You are gonna be sorry for that"
That's all Dean could make out from whatever Cas had mumbled. Cas was only in his boxers and dean was butt naked, but they were both okay with that. As soon as Cas was on his feet he quickly made beeline for the shower. Dean couldn't work out what Cas would do to Dean when he got out the shower. As time went on, Cas was still in the shower.
"Come on Cas there aint gonna be any hot water for me!"
He didn't get a reply, instead five minutes later Cas casually step out the shower and just as Dean was getting in he grabbed dean and pinned against the shower wall and proceeded to jack Dean off, well that what Dean thought. Cas edged Dean and left him high and dry and wondered off to get dressed. Dean thought that was punishment.
He was wrong.
That was part of the punishment. The other half was that when he went to shower and finish what Cas had started he was hit with a blast of freezing water that made it impossible for him to get release.
Dean learned that day you don't mess with Cas in the morning , especially if you want shower sex.
