• Clarke and Bellamy start sharing a bed when they’re not official and supposed to be just friends but no one ever questions it. They both sleep better with the other and it eventually becomes a co-dependent thing.
• Clarke can go days on end without sleep and not show a single crack. She’s used to it, since she’s been helping her mother in the med-bay from age eleven.
• Bell is the polar opposite. He was always a smart kid, but he never got up early because he cut classes on the Ark to look after Octavia. Bellamy can be a real grumpy bastard when he hasn’t slept properly so the Guard learn to avoid tasking Bellamy with back-to-back shifts.
• Most of the time, Clarke is the little spoon. It’s practical because Bellamy likes to hold Clarke and Clarke likes the feeling of Bellamy at her back. But if Bellamy is already asleep when Clarke comes in, Clarke seizes the opportunity to be the big spoon. She puts her head between Bell’s shoulder blades. He complains that her nose digs into his spine but he secretly loves it. 
• Bellamy is a pro at napping. The couch, the Rover, a tree, the floor, his desk, the kitchen table, literally anywhere. Any amorous couple have to check before they do the do in a store cupboard incase Bellamy is in there sleeping, after a previous case in point with Monty and Harper.
• Bellamy’s napping can be a problem for Clarke when he’s obstructing where she wants to be but she hardly ever moves him because she thinks it’s cute asf.
• They both have nightmares. Bellamy gets sweaty and his eyes roll but he never makes a sound. Clarke develops night terrors by the time Skaikru actually get some semblance of peace. It doesn’t matter how many times it happens, waking up to Clarke screaming always scares the hell out of Bellamy.
• Because of her night terrors, Clarke can have trouble going to sleep. Sometimes, to distract herself, she’ll peruse Bellamy, tracing his facial features, curling his hair around her fingers, running her hand down his chest. 99% of the time, Bellamy is awake but pretending not to be. 
• If one of them is ill, the other stays up through the night to watch over them, even if it’s completely irrational. The eventual Griffin-Blake kids get the same treatment, except Clarke and Bellamy take turns. 
• Clarke has a thousand drawings of Bell when he’s asleep. To her, it’s when he looks most content.
• Right up until the day he dies, Bellamy sleeps with a knife, just under the bed where he can grab it quickly. No amount of persuading from Clarke convinces him to stop but he never once uses it. 

I don’t know why you’re arguing with me, Clarke. After all, I’m just a subconscious projection of you.