This is based off two prompts I saw on tumblr. One was that at the beginning of an episode we realize Destiel's having sex and the other is what if Sam was the one hit by a truth spell.

•*•*•*•*•*•*•*•*•*•

The room is dark. In the shadows, on the bed, two person moaning and gasping their love to each other. On a chair hangs a trench-coat and a leather jacket, seemingly having been hurriedly thrown there.

<<<< 24 hours earlier <<<<

Sam, Dean and Cas were hunting a witch. Nothing out of the ordinary for them, except she seems to imbed her victims with a modified truth spell before she kills them.

They manage to kill the witch, but not before she hits Sam with the spell. Dean and Castiel both stare at him, invading each other's personal space, as usual. Standing up, Sam glances at them, scoffs and says "Will you two hook up and make out already?" then leaves, leaving both of them disoriented and staring at each other before they run to catch him up.

Back to the bunker, Sam never stops making comments and pointing out how obviously in love they are.

Seeing them stare again, Sam looses his nerve and pushes Cas, making him fall on top of Dean. Both blush from the proximity, but say nothing and don't move.

"I'm going grocery shopping, you two have sex while I'm gone!" Sam yelled then slams the door, Cas quickly standing up and flying away.

>>>> 12 hours earlier >>>>

When Sam comes back to the bunker, Dean is chugging a beer in the living room and Cas is nowhere to be seen. Sam soon forms a plan, but he'll need help.

He calls Gabriel, who is over enthusiastic over it. Basically, Sam will lock Dean and Cas in a bedroom, with only water and no food. He needed help so Cas wouldn't fly out or snap food into existence.

>>>> 30 minutes earlier >>>>

Sam managed to trap Cas in the room pretty easily, and seeing as it was Dean's room, Dean eventually retreated to it to find Cas sitting on a chair.

The moment the door closes, it shines a bright green light and Cas lets out a sigh.

"I believe we are trapped in here, Dean," Cas said.

"Hells yeah you are." Sam's voice was muffled by the door. "Ok, listen up. You guys are both completely oblivious to the fact that the other loves you back. Gabriel put a spell on this room, you can't get out before you kiss or more and Cas won't be able to snap food. The sooner you confess the sooner you get out."

Dean groaned and sat on the bed as Sam's footsteps left.

"I do love you, Dean," Castiel spoke up, leaving Dean confused and somewhat happy. "Ever since I laid a hand on you in Hell. I just need to know if you love me back."

Startled by Cas' sudden confession and his determined tone, Dean took a moment to answer, passing a hand trough his hair.

"I guess so... It's just, you know, I always thought I was straight— and now I'm in love with an angel."

"Then I guess it's all right if I do this," Cas said, sitting next to Dean and putting a surprisingly daring kiss on his lips, without the hint of a hesitation. Dean took a second to respond, melting into the kiss.

Cas pulled away and smirked at the hunter's expression. That supposedly innocent angel smirked, pushing Dean against the wall.

He tilted his head in a not-so-innocent-anymore manner, the suggestive smirk never leaving his face, sending a shiver trough Dean's spine.

"You know, you hurt me quite a few times, actually. Every time you said we were friends, we were family... nothing more?"

Dean was taken aback by Castiel's sudden change of comportement, but would lie if he said it didn't turn him on for a bit.

"Cas?" He received a low hum in response. "Why are you suddenly acting so... out of character?"

Castiel grinned leaning in to whisper in Dean's ear, his lips brushing against the skin. "It's just another side of me you never got to see," he said, and Dean had no time to wonder about the sentence that a pair of hungry lips came crashing  onto his.

They pulled away for air, Dean's green eyes meeting Castiel's blue ones, now darkened and blown wide by lust, a smirk still plastered on his face.

•• Now ••

Sam sits in the living room wondering what's happening in that room for them to take so long.

"Gabriel," Sam says, the archangel zapping to his side, "What are they doing?"

Gabriel seems to concentrate for a moment, then a shit eating grin formed on his face.

"I believe they are doing the frickle frackle," he says, flying away as Sam giggles. His plan had worked even better then he expected, but the tension had to be cut someday.

I just really wanted a horny Cas, so here it is. I will not apologize for this, though he kinda sounds like Casifer in my head for that part.