A/N: This is just something I thought of randomly yesterday, and thought would be fun to write. Just assume when you read this that Yukio and Rin are in an established relationship. Hope you enjoy!
Beeeep… beeeep… beeeeep…. Beee-
Yukio woke up groggily and silenced his alarm clock. He sat up slowly while rubbing his face. When he looked to his side, he noticed his older brother was there with him, and when he looked down at himself, he realized they were both wearing absolutely nothing. For a moment, he wondered why, then the memories came right back to him.
"N-nii-san… going to…"
"hnnn-! Yukio- please…"
Yukio blushed bright red as he remembered the night before. How many times had it been… three? He looked at Rin with pity, perhaps it would be best to make him take a sick day, he might have a slight issue… sitting.
He stood up and climbed out of bed, careful not to wake his brother, then went to the bathroom to shower and brush his teeth. As Yukio walked by it, he noticed his reflection in the mirror was a little… strange looking. He couldn't see clearly without his glasses, but when he got closer to the mirror to investigate, he noticed that something was very messily written across his chest in black marker that looked to be permanent.
"RIN WAS HERE…" He read out loud softly, gritting his teeth. There were bite marks on his neck and shoulders, and hickeys all up his torso.
Some of which, he noticed, wouldn't be hidden by the collar of his uniform shirt. Hissing, Yukio turned around again, almost moving to go back into the other room, but then he remembered that his cute older brother was asleep on the bed there. He was torn between going and giving him a piece of his mind now, and going on with his day, to come back and punish him later.
Yes… the thoughts of how he could punish his brother for possibly embarrassing him came into Yukio's head. The more he imagined it, the more appealing the idea was. He nodded, decided, then turned to shower and get ready for the day.
He could teach his nii-san a lesson when he got home.