A distorted little AU about Castiel.
Castiel always sits at the back of the class because he so chooses and end of story; he would stand in front of the mirror every morning, lock the bathroom door, and stare down at his lanky frame and trace his hands over his prominent hip bones, suck in his stomach and cup the curves of his protruding ribs in both hands, and then he goes on hating his body and loving the solitude of his own little world, and every morning he would go to class and relive the rush of insatiate lust at seeing Dean Winchester with his congregation in the front, and he'd watch him flirt with every girl around and curse offensive words and look at everybody down the bridge of his nose, and every day he'd go home thinking about Dean's abhorrent, atrocious and repulsive personality, and about how he wants to press him down against the table and fuck the attitude right out of him, and at night after showering he'd press his lips against the fogged up glass and make out with his blurred reflection, suckling and running his tongue over the smooth surface, would tilt his head every way and close his eyes and pretend it's actually Dean he's kissing while taking pride in knowing it's not, 'cause Dean won't kiss him and nobody will so he does it on behalf of the rest of them and it's fucking great, it's immensely invigorating, and his lips would pull away with a wet noise and he'd take deep breaths through his nose and get down from his tiptoes and go to bed, wake up the next morning and lock the bathroom door behind him.
And maybe one day Castiel will veer from this routine and accidentally let slip some of the things he wants to do into the shell of Dean's ear, hot breath blowing and lips grazing ever so slightly the soft hairs on the reddening tip and he'll plant a chaste kiss to the base of Dean's taut neck and carry on walking down the aisle, when he would turn around and smile at Dean and relish the expression of absolute horror on Dean's features at the disgustingly homosexual act perpetrated against him and Castiel will laugh knowing Dean would look just as haunted when he turned around, and he'll enjoy the surge of power every time their eyes met when Dean's would snap away sharp like ice while his remain unrelenting, and he'd take pride in knowing that one smile can send every thought of joy and comfort and security and every drop of blood scattering from Dean's head and he'll look back with a hollow fear so delicious on the tip of his tongue, and he'll own Dean, finally, finally, because he'd pierced him with a spear and he owned every hair every glance every breath of the boy who is now inevitably and irrevocably and inexorably bound to him, drawn to him, and Dean will come to him by his own free will and let Cas thread their fingers together and make love to him on the table, floor, bed, let him kiss the crook of his knees and leave inklings of little flowers blossoming in the wake of his lips, nudge his head tentatively between his legs and please him until he's screaming, or until he understands that No, hush, don't tremble with fear but love and love and devotion and a lifetime plus a million years of staying by his side and that's all, all that Castiel has ever wanted him to understand.