new favorite headcanon right here

Surprisingly, Sam’s the first one up. Usually Dean has already downed two cups of coffee by the time Sam gets to the kitchen, but today there’s nobody in sight. 

He’s trying to figure out how to work the coffee maker (again, Dean is usually the one to do this) when Cas says from behind him, “Morning, Sam.”

Sam turns and returns the greeting, still thrown off guard by Cas’ pajama pants and old t-shirt despite the fact that he’s been human and staying in the guest bedroom for a couple of weeks now. Cas sits at the kitchen table and tiredly runs a hand through his messy hair. Sam wonders if Cas thinks it’s weird that Dean’s not up yet, but he doesn’t ask.

They sit in silence as they drink their (mediocre) coffee, which is probably why Sam nearly has a heart attack when Dean slides into the kitchen with a “WOOOO,” fuzzy socks on his feet and a robe tied closed around his waist. He starts playing an air guitar and making the sounds himself since there’s no music actually playing.

Sam looks to Cas for reassurance that this doesn’t make any sense, but Cas is staring down at his phone and drinking coffee like this is normal.

“Morning, Sammy!” Dean yells before leaning over and kissing Sam on the top of his head.

“What are you–”

“Morning, Cas!” Dean interrupts as he places a kiss on Cas’ head, too.

“Good morning, Dean,” Cas states without looking up from his phone.

Dean then heads over to the coffee maker–or, rather, he dances over to the coffee maker–while humming some unidentifiable tune. “Jesus, Sammy, you suck at making coffee,” he announces emphatically before picking up the whole coffee maker and theatrically dumping all of its contents into the sink. 

He continues humming and dancing as he makes his own pot of coffee, and then when he joins them at the table he’s got a huge, goofy smile on his face like it’s the best day of his life. His smile changes to an overdramatic wince, however, when he takes a seat. He stands back up and sits back down slower before deliberately adjusting his butt in the chair. Sam glances over at Cas and sees that he’s now smirking down at his phone.

“How was your night, Sammy?” Dean asks way too loudly.

“Um, it was good.”

After a beat, Dean continues, “Aren’t you going to ask me how my night was?”

Cas sighs and looks up at the ceiling as he says, “Dean, we agreed not to tell him until–”

“CAS AND I HAD SEX LAST NIGHT.”