Sam thinks that everything about these two is ridiculous. They've been at the bunker for weeks, there's been nothing much on the supernatural front, which is good because Cas is still adjusting to being completely cut off from heaven.

It's the small things he notices. They'll be watching the TV or reading and Sam will see how Dean sways immediately to the seat on the sofa next to Cas, whether consciously or unconsciously Sam can't tell. Then he'll sit just that little bit too close to the ex-angel. Cas started that of course, back when they first met and Sam had just laughed at the angel's little peculiarity. Now though, they both do it and Sam knows for a fact they both know better.

Or they'll be eating dinner. Cas will push the plate away, food unfinished and Dean immediately jumps in with 'What's up?' leaning towards Cas and catching his eye, a worried crease between his eyebrows. Cas murmurs back he's not hungry but Dean will still keep watching him warily as he finishes his own meal.

After dinner they might still be sat at the table when Dean will get up to the sink and start cleaning the dishes. Sam almost counted all the way up to 15 once before Cas had stood up and followed him over, hovering awkwardly for a moment before Dean throws the tea towel at his and tells him to start drying the things on the rack.

Cas, still not used to the concept that his human body will tire and he needs to go to bed at night, often falls asleep in the middle of an evening's task. Sam walks into the main room in the mornings to see Cas, still upright in his chair at the table or flopped sideways on a sofa in the library, the book he was reading fallen across his chest and moving steadily with his breathing. Every time he walked in to this he could guarantee his brother would be right there, in the opposite seat at the table or draped on the other sofa. Sam also knew what a light sleeper Dean was and could tell when he was still pretending to be asleep. In these instances he would pretend to ignore them, walk through to turn the coffee machine on and listen as Dean sneaked back to his bedroom to act like he'd woken up in there.

Sam might hear Dean shout from the other side of the building, "Sam, bring me my phone, it's in my room." Out of a reluctant obedience instilled into him as a younger brother he trudges to Dean's bedroom, grabs the phone from the ledge and turns to see Cas jerking to a stop in the doorway, looking surprised and slightly disappointed. With a roll of his eyes and no comment Sam walks past him, pressing the damn cell into the other man's chest and going back to his own task.

It's the smallest thing that really gets him though. Small but incessant.

Cas nodding at the table late at night, eyes drooping before he jerks back upright with a look of confusion and indignation on his face. As his eyes settle back on the page and they're sure he can't see them, that's when Dean will look up and his face just softens into a smile. Not mockingly, it's an expression Sam could best describe as thankful.

As Dean stands at the sink, eyes focused on the soapy dishes in his hands, Cas will watch and wait next to him, towel poised. Then he will glance up to Dean's face, eyes tracing every curve and freckle. Cas' expression will suddenly be transformed to a look of silent bliss as he smiles across at the hunter.

Maybe Dean sits fiddling with his pocket knife at the kitchen table, Sam sat opposite with his laptop. Cas walks into the room and crosses to get a mug from the cupboard, possibly straying closer to the table than is strictly necessary, allowing his hand to just lightly trail over the back of Dean's chair. Sam looks up just in time to see the corner of his brother's mouth curling up as his head stays bent down. Cas is absentmindedly smiling as he walks away.

On and on, every time they think the other isn't looking, there's this dance of secret smiles. Sam pretends he doesn't see; he's not going to meddle in whatever this is and he is not going to be the one to mention that 'this' is so blindingly obvious. Still, with this game they're playing, Sam isn't sure if he is the only one who sees it. After all, they're never looking at each other; it's always carefully stolen glances and an abruptly shifted gaze when the other looks like they might be turning their head.

One evening they sit together, heads apparently buried in separate tasks but all very much distracted. Sam is fascinated; he thinks it's almost choreographed, as Cas' gaze and gentle smile turn back down to his book and almost simultaneously Dean's eyes flick up, lips quirked fondly. For two people who spent the last 4 years staring into each other's eyes, Sam just can't work out how they can be this bad at seeing each other.

When they miss each other for the third time in less than 5 minutes and Sam realises he hasn't actually looked at his laptop in over 10 he closes the screen down and stands up. Dean and Cas look up at him in faint surprise.

"Alright, I'm done." He says, running a hand through his hair. His brother and the former angel glance at each other, obviously looking for some explanation. When Cas turns back to look at Sam, Dean's gaze lingers a little longer. "Oh, Jesus!" Sam exclaims and with that he turns and walks to his room.

Dean and Cas watch him go, somewhat bewildered. Then Cas' low voice rumbles through the quiet left behind.

"I wish he wouldn't blaspheme."

Dean turned with an amused smirk. When his eyes met the other man's, Cas was grinning right back at him.