Light, after careful observation, had finally come to a strange conclusion.
L had an oral fixation.
It wasn't that hard to put together, really. If there wasn't some sort of spasm-inducing sweet being shoved into the genius' mouth, his thumb would be, teeth marks spread up to the knuckle. He also had an uncountable stash of lollipops hidden everywhere, including (Light discovered unfortunately one night) under the pillows of his bed.
It had taken three washes for Light to completely get the bright purple out of his hair.
Light had tried to confront L about it in a serious and mature matter, but when L couldn't answer because he had seven sticks of Pocky in his mouth and a crepe in his hand, Light took more drastic measures.
It started with locking L in the bathroom and latching a chair beneath the doorknob so even if he unpicked the lock he couldn't get the door open, (Unless he had a hatchet slipped inside his very, very loose shirt.) And while Light was suspicious, he was willing to take that chance.
After that (He didn't know why he was spending precious time on this endeavour but damn it he was.) he set about tearing the room apart, cleansing the room of anything that could be held in L's mouth for a long amount of time and not melt. The lollipops were first to go – if he had to watch the shadowy genius suck gently on another kiwi bonbon surprise he was going to scream – and he could almost imagine L spread pitifully across the bathroom door because he knew.
The crepes he decided to keep. Okay, a crepe he decided to keep. And really, he was being generous. And he was almost positive that L didn't like chocolate mint anyway. (Almost positive, when L was released to discover his kiwi bonbon surprises were gone he might do drastic things.)
"Kira? Kira what are you doing?" the muffled whine resounded across the bedroom, and Light could see one large dark eye in the gap beneath the door, half shadowed by the chair.
cleaning." Light said with sadistic sweetness. "And I'm not
"But only Kira would be so mean as to – my crepes!!!"
Light tried to keep up appearances around L, 'don't let your guard down' and all that. But he couldn't help but feel that good old feeling of psychotic pleasure at the horrified squeal that echoed around the room.
It was nighttime, and Light had released L from the bathroom a good few hours ago. He was finally convinced the detective was asleep and was just preparing to nod off himself, when he felt a strange sensation.
"Are you… Are you sucking my thumb?!"