A/N: A sort-of late birthday present for my ever-valiant beta, Sarah_Ellie! She demanded porn, so I provided!

"You're not studying, Dean," Cas reprimanded him, nose mere inches away from her Latin translations.

It was a sunny Thursday afternoon with finals just around the corner, and they were in the back of the library. It was Cas's favorite table, partially because it was out of the way and quiet, and partially because of the nice, big window that let sunlight shine perfectly on the table. Cas could see Dean out of the corner of her eye, uniform sleeves rolled up and tie loose around his neck with a couple buttons undone, very clearly not studying.

Dean sighed heavily. He was slumped forward over the table, one arm curled across his textbook, his chin resting on his wrist and the other arm stretched across the wood surface separating them, his fingers twirling around a string of her hair distractedly.

"I'm boooooored," Dean complained, "We've been at this forever."

"Or, in fact, half an hour," Cas corrected, turning her head slightly to write a note in her notebook, "Dean, seriously, you've got to pass, get studying."

"I have," Dean huffed, "I just can't do it all in one go like you can. You're a freaking machine."

Cas sighed, but didn't bother to answer, turning the page instead and continuing to read as Dean's hand in her peripheral vision twirled and slid her hair through his fingers.

Dean managed to not be distracting for an impressive full minute before he was sighing heavily again, the gust of air flicking at the corner pages of her book. He apparently decided that was entertaining, because he started to blow air through his lips gently at the pages until they flitted up and down slightly.

"Dean," she said sharply, finally looking up at him with a glare and Dean groaned, giving her a pouty face. Cas absolutely refused to be seduced by the way the sunlight coming through the window was turning those green eyes into chips of glass and his hair into a blond halo, though she knew he was aware of it and trying to use it to his advantage. Dean may have the mental discipline of a goldfish, but she didn't.

"If you want a study break, take it," she said sternly, "But I am trying to read, so you need to be quiet."

Dean sighed and pouted more heavily, but Cas turned back to her book before he could lay the full effect on her. She managed to start really digging in before she saw Dean move, letting go of her hair to sit back. She assumed he was getting up to go hit the vending machine (that boy could eat all-day, every day, it was ridiculous), but instead, he was suddenly under the table, his hands on her knees, pushing her skirt up.

"Dean!" she squawked in a whisper, looking around in mortification as she tried to jerk her legs away without kicking him, "What the hell are you doing?"

Dean pressed his chest against her knees, hands trailing up and down her calves as he laid a trail of distracting kisses along her thighs, "You're too stressed about these tests, Cas. You're brilliant, you'll pass with flying colors."

"I fail to see how that explains why you-"

"Oh, come on, Cas," Dean said sweetly between kisses, pressing his open palms on her thighs and sliding them up slowly, bunching her skirt up to her waist, "I'm bored and you're tense, let me take care of you."

This was a monumentally bad idea, Cas knew. They were in the library, for god's sake, anybody could walk by, the librarian or- god help them- a teacher!

Then again, Dean was sliding his fingers under the edge of her panties, brushing gentle caresses along her hip bones that made her belly twitch.

Cas bit her lip as she reached under the table, following his arm to his shoulder and then his face. She traced his jawline gently to his mouth, where she could feel the corners of his lips pulled up in a grin.

He kissed her fingers sweetly before nudging her legs apart to make room for himself, taking her silence for the assent it was and scooting closer on his knees.

Cas's hand returned to his shoulder as she looked around again nervously. This was definitely what everyone meant when they warned her about Dean Winchester when she came to this school. Granted, that was over a year ago now, and she had had plenty of opportunity to experience exactly the kind of trouble Dean was capable of being, but it seemed like every day he found something else to do to surprise her.

Right now, it was how calmly he was pressing his mouth to the outside of her panties, breathing hot, humid air against her slowly as his hands continued their circuit over her legs. First trailing down her thighs, then over her knees and around the back of her calves before cupping her ankles briefly, his big hand able to wrap around them entirely without effort. Then the whole thing again in reverse.

"Smell so good, Cas," Dean said quietly, pressing a firm kiss against her as he breathed deeply through his nose, making her blush, "God, love getting my mouth on you."

Cas shivered, clenching the edge of the table in one hand and Dean's shoulder in the other as he opened his mouth, tonguing at her clit through the fabric briefly before pressing against her and closing his teeth gently. Cas's hips jerked at the pressure, and he slowly slid back until her flesh slipped free and he was left with only the damp fabric between his teeth.

He let go, the fabric snapping back in place and Cas gave a small gasp, earning her Dean's satisfied hum against her clit which made her squirm. His fingers trailed up to the waist of her panties leisurely.

"Lift up, baby," he murmured, tucking his fingers over the edge of the fabric and tugging them down. Cas obeyed, canting her hips up for him to slide them down and off.

Dean took the opportunity to pull her hips forward as well, closer to the edge of the seat to give him better access and Cas couldn't help the way her legs fell open wider on a pleased sigh.

"Oh yeah," Dean breathed, hands curled around her hips and nosing at the dark curls at the top of her mound before sliding down to the smooth, shaved skin below it.

Cas's breath stuttered when he licked a broad, flat stripe from her opening to her clit, tongue pointing at the end to flick across the sensitive bud. He did it again, lingering longer at her clit this time, using a rolling up and down of the tip of his tongue to make her twitch and pant.

Dean slid his hands further in, dipping his thumbs between the V of her thighs to spread her pussy lips open and Cas let out a little breath that was almost a sound as his tongue dipped to collect the dampness already starting to slick her folds.

Dean hummed at the taste, swiping his tongue from side to side languidly before sliding slowly upwards. Cas couldn't help the small, soft whine when Dean licked her clit, the open way he was holding her allowing for more direct contact and Dean responded immediately to it; sealing his lips over the pink bud and beginning to swirl his tongue in a random, dizzy pattern.

Cas tightened her grip on his shoulder with a barely-suppressed moan, biting her lip to stay as quiet as she could while Dean licked jolts of pleasure into her. Her head fell loosely back when he started adding little sucks between every flick of his tongue, the sharp bursts of pressure on her clit so good her hips reflexively pressed up against his amazing mouth.

Dean was panting, the puffs of hot air from his nose tickling across her pubic bone and her legs shook, simultaneously wanting to tighten around him and fall open wider to his insistent tongue.

"Ah!" she panted when he suddenly sucked harder at her clit, mouth pressed tight against her and making her inner walls clench with want. Her hand flew up from where it was holding the edge of the table to clamp over her mouth hurriedly, suppressing the sound as best she could.

Dean groaned when he heard her, the noise muffled in her hot flesh and making her arch, her slick passage clenching fluttery and empty, longing for something to fill her. Like a mind reader, Dean's fingers were suddenly there, pressing two thick digits inside her slowly to the last knuckle before curling forward on the way out.

Cas's fingers bunched the fabric of his shirt in a tight grasp as the culmination of Dean's tongue and Dean's fingers rubbing her exactly right made her come, trembling and panting. Dean didn't let up for a second of it, coaxing wave after wave of pleasure from her until it was overwhelming and she had to pull him away; hand going from his shoulder to his hair and tugging sharply.

Dean hummed in pleasure, and Cas risked looking down at what she could see of him under the table. She gave a small groan at the sight, nearly pressing his flushed lips back against her when the sunlight from the window made her slick wetness shine across his mouth and chin.

Dean's mouth quirked up at the corners as he slid his fingers out of her carefully, licking open-mouthed around his lips as he panted hot over her thighs.

Cas blushed when he stuck his fingers in his mouth to lick them clean of her juices while his other hand fumbled for her panties on the floor beside his knee. He was gentleman enough to straighten them out when he found them so he could guide one foot, then the other, into the proper openings and slid them gently up her legs. She lifted her hips weakly again to let him push them back into place, and stroked his hair when he pressed a final, warm kiss against the front of her panties, a perfect bookend to the kiss he had used to get things started.

"Now that's what I call a study break," Dean purred, straightening her skirt neatly and wiping his mouth as he got out from under the table. Considering that she was the one who had just had a great orgasm in the middle of the library, he looked more mussed than she did, hair tousled from her fingers gripping it, the shoulder of his button-up hopelessly wrinkled and his face flushed.

His eyes were shining with pleased amusement, and she knew from the wide-blown black of his pupils that he was hard, probably had been since he had put his mouth on her. For a moment, she felt a bit bad that she had got off and he hadn't.

Then she had an idea.

"Tell you what," she said, still a little breathless, and Dean immediately piqued with interest, "Let me finish my translation, you finish memorizing your declensions, and I'll return the favor. Deal?"

Dean grinned, licking his lips as she forced herself straighter in her chair and pulled her textbook closer again.

"Deal," he purred, opening his notebook like challenge.

Cas watched him turn to the book determinately, captivated by the way Dean kept rubbing his fingertips across his lips as he read, inhaling her scent off his fingers. If he could motivate himself to memorize latin declensions with the taste of pussy on his tongue and her smell in his nose, he'd earn a lot more than a blowjob.

Maybe she could challenge him to list them while she blew him, promising a fantasy of his choice if he succeeded.

Now that would be motivation. Maybe she could turn him into a scholar yet.

A/N: I think this is the first time I've written detailed cunnilingus in my fanfic career... Hopefully it went pretty well!