Castiel hated going to bed.
The first time was when the fallen angel and the two Winchesters were at Bobby's house, gathered on the small sofa, watching a movie on the small screen.
His head fell forward, jolting himself awake when it fell too far, too uncomfortable.
When the two men declared they were going to bed shortly afterward - it was rather late - Cas followed their lead, and they all made their way over to where they were sleeping.
They settled into their beds - if they could be called beds - and fell asleep quickly. They could tell with just a glance that the fallen angel had an issue he wasn't sharing.
The brothers watched him with careful eyes the days after that.
Every night, Castiel would sit up with Sam and Dean, laughing with them, drinking with them. He wouldn't go to bed unless one of them - or both of them, the vast majority of the time - was heading there themselves.
Dean wanted to believe he was just taking social cues from the pair of them - if they were going to bed, it would be a reasonable time to go to bed.
It wouldn't be a problem if the two brothers had a fucked up sleep schedule. Hundreds of all-nighters and the constant driving all over the country really messes with ones' sleeping patterns, meaning the boys could last on only a few hours sleep - so they boys took late nights and early mornings.
Which meant that Castiel would be tired before going to bed. Most of the time it was around 2 o'clock in the morning, when the three would finally go to bed.
On the plus side, Cas didn't wake when they did, so he managed to get a somewhat good night's sleep, before he had to be up for breakfast. Or a case.
It was unfortunate that they hadn't realised what was going on until after a week of falling asleep on the sofa, when it finally clicked that he was trying to wait up for them.
It was cute, really.
Dean spoke to Cas quietly, after dinner on the eighth day of their stay at Bobby's.
"Cas, if you're tired, you can go to bed, y'know. You don't have to wait up for us, and copy us - heck, never copy us when it comes to sleeping patterns. It's not like we're gonna laugh at you just because you're tired.
"It's not just that." The fallen angel murmured to the ground, feeling a slight blush flood to his cheeks. "I don't like falling asleep alone."
Cas kicked at something small and imaginary.
"Nightmares?" Dean nodded in understanding. "I get it, I really do. You don't wanna fall asleep without someone there, because it brings bad dreams. That's the worst."
The blond hunter thought for a few minutes, finally coming up with a solution.
He hadn't told anyone what his plan to help Castiel was, but he was looking pretty damn proud of himself as he sat himself down on the sofa. Sam had settled into the small armchair, and the elder brother patted the seat next to him, the fallen angel sitting in the place indicated.
"Tired?" The blond asked the man next to him, and he received a small nod in response.
From the floor beside the sofa, Dean picked up a fleece blanket.
He covered the fallen angel in the blanket, and wrapped his arm around the smaller man's shoulders, pulling his head down onto his own shoulder.
"Use me as a pillow - that way you'll be able to get some sleep and you'll also be comfortable - you're really nice and warm, by the way - and this way you're not alone. We'll wake you when we're gonna go to bed, okay?" this was whispered into the dark haired man's ear, as the arm around his shoulders squeezed reassuringly.
Castiel fell asleep after only a few minutes, and, in the following days, he seemed less tired - more efficient. And happier too.
Dean was glad his plan worked, and he secretly longed for the time Cas spent asleep on his shoulder. It was so comforting, and he tried not to dwell on the feelings too much.
'It's the sense of pride in yourself for coming up with such a good plan.' he tells himself.
He's not too convincing.