Disclaimer: The characters in this story do not belong to me.
He honestly didn't know why it surprised him so much. The way Ryuuzaki constantly gnawed at his thumb during the day, it shouldn't come as a shock to know he sucked his thumb at night. Still, this mysterious and genius detective doing something so immature and so human felt somewhat unnatural, like seeing a wolf on a leash.
The first night Raito noticed, he didn't do anything. For a moment, he stared at the spectacle as if this was just another inane Kira test that he must decipher and pass. Maybe he wants me to wake him up and prove I'm Kira? Or maybe he thinks Kira would leave him asleep and laugh at him…does that mean I should wake him up? For some time, Raito stared; and for some time, Ryuuzaki did not move. After a while, Raito finally shrugged it off and turned over on his side, hoping the sudden clinking of the chain between them wouldn't wake the detective. The next morning, nothing was mentioned.
The next night Raito spent with Ryuuzaki, Raito allowed himself to experiment, taking hold of the other boy's wrist and tugging it gently out of his mouth. Ryuuzaki stirred, but did not show any signs of regaining consciousness. Raito watched with vague amusement as a moment later the thumb was replaced. Raito repeated the action, this time keeping his hold on Ryuuzaki. Again, the older boy shifted uncomfortably but remained asleep. Raito sat frozen, his fingers still clamped down on Ryuuzaki's hand. A brief eternity passed, and then Raito felt Ryuuzaki begin to move again.
Raito resisted the urge to pull away when his own thumb was brushed against Ryuuzaki's lips. Something inside him twisted uneasily. Discomfort, he figured, for being this close to his enemy. He was still a moment, trying to decide if it was too risky to move at this point. Before he could decide on an answer, his thumb was in Ryuuzaki's mouth.
Raito gasped, instinctively going rigid. Ryuuzaki was seemingly unaware of the fact that the thumb wasn't his own and sucked at it contentedly, almost as if in a trance. Raito swallowed thickly. He wondered if he should try and escape, but his thought process hesitated when he felt Ryuuzaki run his tongue slowly over his skin. "Ryuuzaki…" he whispered quietly, not sure if he wanted to wake the other boy or not. Ryuuzaki responded by gently biting down on Raito's knuckle. The twisting in Raito's stomach was becoming almost painful. Ryuuzaki dragged his tongue over Raito's thumb again. Was this all still a test?
It was getting hard to concentrate. Raito felt his heart rate quicken as Ryuuzaki pulled more of his thumb into his mouth. How could this possibly feel so…sensual? Raito let out a heavy sigh, resisting the urge to moan. Suddenly, Ryuuzaki stirred, pausing in his ministrations.
Worried that the other boy would wake, Raito quickly removed his own thumb and replaced it with Ryuuzaki's. He made sure to sleep on the far end of the bed. The next morning, nothing was mentioned.
The night after the incident, Ryuuzaki feigned sleep. He was well aware of his slightly embarrassing habit and popped his thumb into his mouth in order to lower any suspicions. He had noticed Raito acting differently earlier that day, but when he questioned the boy's health, Raito pretended he didn't hear. It was very questionable behavior. Kira-like behavior. Something Ryuuzaki felt he should look into.
In the middle of the night, the detective became aware of Raito looming over him; watching him. He pretended to be oblivious and waited to see Raito's coarse of action. He was mildly surprised when he felt fingers wrap around his wrist and guide his hand from his mouth. Was this what Raito was acting so strangely about? Was it just that he knew Ryuuzaki sucked his thumb?
Raito placed a hand on Ryuuzaki's shoulder and, without warning, slid two of his fingers into Ryuuzaki's mouth. Ryuuzaki kept himself from gasping and acted as naturally as possible, squirming slightly as he felt Raito's other hand wander to his hip. What was Raito doing? Ryuuzaki shivered at the sound of Raito letting out a quiet groan. What had possessed him to go on with this ritual? How many nights had he been doing this? Why had Ryuuzaki never woken up? Ryuuzaki's questions were interrupted when Raito pulled his fingers out of his mouth, replacing them, regrettably, with his tongue.
Ryuuzaki had never been kissed before, and as he allowed Raito to plunder his mouth, he wondered if this was it. Not that it was unpleasant, but Ryuuzaki found it to be, over-all, a little underwhelming. It went through his head that there was a 78 percent chance it would be better if he were kissing back, and then, suddenly, Raito jumped back. "R-Ryuuzaki?" His voice sounded shaky, very uncharacteristic; not very Kira-like at all.
Ryuuzaki furrowed his brow. He didn't even get a chance to see if there was an increase in enjoyment. Without spending too much time analyzing the consequences, he lifted his head to continue the kiss. Raito was shocked for a moment, but then groaned, shifting so that he was straddling Ryuuzaki's hips. This was much better. Raito pulled away for a breath, looking questionably at Ryuuzaki, whose face was blank.
"What are you doing?" Raito asked, feeling slightly ironic that Ryuuzaki was not the one asking that question. Ryuuzaki shrugged and said nothing. He glanced toward the door and then back at Raito, a calm smile playing at the corners of his lips. When Raito asked again, trying to show he wanted an answer, Ryuuzaki captured his mouth again. Raito decided an answer wasn't that important.
Raito's hands skated up Ryuuzaki's shirt and ran up and down his chest. He made no definite signal to remove the shirt, and thus it stayed a thin fabric barrier between them. At one point, Raito felt Ryuuzaki's hands clasp at either side of him, but they stayed irritatingly on top of his undershirt. Eventually, his left hand wandered only to nest comfortably in Raito's hair. Neither Raito nor Ryuuzaki felt this was enough contact, but neither of them did anything about it.
It was over as suddenly as it began, and they both rolled to their respective sides of the bed, the chain clinking between them, keeping them from letting shame get the better of them and scooting to the extreme opposites of the bed. Neither fell asleep that night; listening in wait for the other to do so.
The next morning, nothing was mentioned.