Sam Winchester never considered himself a genius. He worked hard throughout school, getting straight A's no matter school his father dumped him and Dean into. He even went to college. He spent four long years at Stanford, and almost got a free ride through law school. But no he wasn't a genius. Except he still would've thought he'd have seen this.

He started to notice little changes in Dean after they got Cas back from purgatory. He seemed… happier. He wasn't all "You didn't even look for me, How could you?" anymore. He jumped at every opportunity to be with Cas. Then, when Cas decided he wanted to be a hunter, Dean practically did the happy dance. Sure in the past Dean always seemed happier when Cas was with them, and when he made a mistake, Dean had the same reaction he always had when Sam himself had messed up. Disappointment, anger, and worry. He'd always chalked that up to Cas being like a brother to him and Dean. But after Cas took the angel tablet, Sam started to wonder whether it was brotherly affection or something more.

But even with his suspicions, he wasn't expecting this.

He'd only stepped out for 15 minutes. He'd gone to get burgers and some pie upon Dean's request. Sam pulled up to the motel where they were staying at. They were investigating what they'd decided must be an angry spirit haunting. Sam parked the Impala in a space near their room and got out. He pulled his key to the room from his pocket and inserted it into the lock, the door swinging open.

And his jaw proceeded to hit the floor.

They were on the sofa, Dean straddling Castiel's lap, kissing more passionately than any kiss Sam had ever given to anyone. Including Jess. Suddenly, it all made sense. The over protectiveness of each other, the frustration when they made mistakes, the stolen glances when they didn't think the other was looking. Dean and Cas were in love. Sam watched as all the pieces fell into place. Of course, he mentally slapped himself. How'd he miss that?

Apparently, Cas must have noticed his presence, because suddenly he was pushing Dean from his lap and standing swiftly to face Sam. "Sam. We were not expecting you back so soon. We were just discussing the case."

Sam stared at Cas, a knowing smirk growing on his face. "Yeah, I'll bet you were." He moved to the table and began unpacking the food. Dean came over to help. "Dude! You forgot the pie!"

"Sorry Dean."

"Yeah well at least you got my bacon burger."

They sat in silence, eating their burgers (or in Sam's case, a salad) and just enjoying each other's company while Sam ran the memory of his brother and their personal angel making out on the sofa.

"So you guys wanna tell me something?"

Dean and Cas exchanged a glance. "No..."

Sam chuckled, knowing that neither one had any intention of letting him in the big secret. So he took matters into his own hands.

"You know its ok for you two to be together, I mean I won't judge you or anything." The angel and the righteous man looked up with wide eyes and alarmed expressions. "How did you..?"

"Well it really isn't rocket science. I could see something was up by the way you guys were acting. But it was the little display about fifteen minutes ago and the couch that confirmed it."

Cas looked like a deer caught in headlights. Dean thought it was adorable. Dean smiled widely and looked back at Sam.

"It's about time you got with the program, Sam!"