1,1k, warning: nsfw, fluff.
One day, Dean finds out that cas sometimes reads his mind. He knows that the angel can do it, just never fully realized that he actually would.
At first, he feels slightly awkward. Cas can read his friggin’ mind, and that place ain’t always sunshine and rainbows. Or, in fact, it’s actually a bit too much rainbow at times. But then he realizes he can easily manipulate what Cas catches up from his thoughts. He’d started to notice similarities in the angel’s mannerisms every time he read Dean’s mind; he would pretend to be busy, get quiet and squeeze his left hand into a fist, or casually drag a finger across his chin.
He didn’t do it often, and Dean had started to learn to catch up on what Cas would do beforehand. Dean started to imagine giving Cas access to only a certain part of his thoughts. He wasn’t really sure how he did it and would never be able to explain it to anyone—but it worked. It went on like that for a while. Dean never spoke about it, and Cas didn’t either. Dean would make Cas believe that he thought about the case, the Impala, Sam, food, some deeper stuff to make sure Cas didn’t think he was entirely numb inside. Once, Dean intentionally thought about an ice cold beer. A moment later, Cas suddenly got up to get him one.
“Funny,” he’d said, giving Cas one of his charming smiles. “As if you can read my mind.”
Then, on a specifically boring day, Dean has the urge to play around with it. It had been going on for so long, and Cas still didn’t seem to realize that Dean was aware of it. He never stayed around in Dean’s brain for long, just enough to see what he was thinking of. It felt like checking up, as if he was worried, and Dean couldn’t blame him for that. In fact, he would do the same to Cas if he was able to. But he was ready for some fun.