Chapter Text
Derek slumped against his bedroom door as he clicked the lock into place. He was done with today. Homework be damned, he was exhausted and he just wanted to chill, maybe jerk off, then go to sleep. Mondays always sucked, but this one in particular was just a shit storm.
He and Casey got in a very loud, very public fight at lunch, during which she shot nasty remark after nasty remark and he laughed them all off and taunted her and tried his damnedest not to feel heavily aroused by the flush of her face and how close she was getting. She was close enough to grab and kiss and grind against - he’d bet money it’d make her shut up. Or not, in a much better way. He’d felt his ears burning at his own imagination and smacked her lunch onto the floor to compensate. She stormed out of the cafeteria, but not before he caught the glossy teary eyed look on her face.
He clunked his head against the door a few more times at the thought. Pissing off Casey was fun, making her frustrated and flustered was hot, but seeing her actually hurting was something he kind of regretted. He let his head fall hard against the door one more time and then turned to shuffle to bed. He tore off his shoes and his pants, shrugged out of his shirt and threw himself onto his unmade pile of sheets, flumping onto it and enjoying the squeak of the springs in protest.
He smacked the play button on his stereo and let his music blast much louder than it probably needed to. Propping himself up on his pile of pillows, he stared at the wall across from his bed, the thin wall that stood between him and Casey. He let himself imagine what she was up to and he was a little disappointed that he imagined her doing mundane boring Casey things. She was probably writing a poem or doing next week’s homework or reading some enormous book for pleasure. She probably in those stupid button down pajamas, the ones with clouds and stars on them, laying in bed, wrapped around a pillow, getting more and more frustrated with his loud music.
He palmed himself through his boxers and tried to think about something else, some hot girl from school or a swimsuit model from sports illustrated, but he kept seeing long brown hair pulled in a tight ponytail, pink lips hanging open in disgust, blue eyes bright and twinkling with a challenge. He hissed as he felt himself grow hard in his hand at the thought of his keener step-sister. He wanted her to think about him, wanted her to turn red in frustration, wanted her to pull his hair, and shout at him, and show interest in what he was saying, even if it was in rage. He let his hand slip through the slit in his boxers and his head thud back against his headboard as he started to stroke his cock with visions of Casey running though his mind’s eye.
Casey shouting at him from across the lunch room, Casey whining about his attitude and his lack of respect for her personal space, Casey turning pink when he touched her, Casey twitching slightly when he slid his arm around her waist, Casey’s eyes growing dark in anger and maybe even desire when she glared at him. Casey in her stupid button down pajamas, standing in front of him, fiddling with the buttons and refusing to make eye contact as he pulled her close to him. Casey breaking his name the way only she does, quieter than normal. Casey Casey Casey.
He was panting now, eyes screwed tight, heart racing and hand pumping fast over his aching erection, making small thrusts into his grip. He groaned low, feeling it mix with the music, feeling light headed. He was so close. Then she was there, pounding at his door, shouting at him, breaking his name and whining, and he was losing it fast. He sat up, eyes locked with the shaking thudding door and imagined it was his headboard thudding as he thrust against her. He listened hard for his name on her lips and imagined it being said in lust rather than anger. He thought of Casey in her pjs at his door as he touched himself thinking of her, while she had no idea, and he groaned, this time a little louder half hoping she'd hear it, as he came onto his fist.
He went limp, breathing hard. Then he scurried to his feet, heat flooding his face as he rubbed his cum onto his shirt from earlier, before throwing himself against the door-frame, undoing the lock, and throwing the door open. Derek looked at her, at her hair falling out of her ponytail, at the flush on her cheeks from yelling, at her heaving chest as she breathed just as hard as him, and knew he was royally fucked.
Casey was looking at him in expectation, waiting for the retaliation, waiting for the poor attitude and rude words, but he just stared at her. His eyes looked dark, he looked flushed, and he was wearing nothing, but boxers. She stepped back and shook her head.
“Turn your noise down, Derek, some of us need to sleep so we can do something with our lives.”
She turned on her heels and marched back to her room, feeling his eyes follow her all the way there. She slammed her door shut and fell back against it, hand on her chest, feeling her heart flutter as she thought of him. Too much. She felt too much. She tried not to think about what he had been doing before she’d knocked, but she was clever and she knew and she felt pangs of heat in her belly and a slickness in her panties and she felt too much at this realization.
Mondays always sucked, but this one in particular took the cake. The fight she and Derek had had a lunch had taken its toll on her. She knew she was blushing as they traded insults, knew she was getting too close, knew she was getting too wound up by his smug grin and heavy looks and tense words. She knew that when his ears lit up red that he was thinking of something inappropriate, something about her, and knew that it was going to make for a messy end to the fight. With her lunch dashed on the floor and his victorious laughter ringing in her ears, she had made a mad dash out of the cafeteria and found the nearest empty unlocked classroom. She wiped tears from her cheeks and fought to breathe as he filled her head. Her frustration was sexual as well as from anger and she knew it and she hated it.
Her thoughts returned to the present, returned to her current frustration, returned to the heated images of Derek, fresh from masturbation, pressed against the door, looking at her with red ears and dark eyes. She knew it was so wrong, so very wrong, to be turned on by that, for so many reasons, topping the list being that he was her brother. STEP brother, said a voice in her head, a voice that sounded a lot like Derek’s. She moaned and flew into her bed, turning off the lights and curling up in her blankets, trying to block out her thoughts the way she used to try and hide from monsters. Nothing bad could find her when she hid under the sheets, not the boogeyman and not her driving urges. In the dark, she could hear the silence and realized that Derek had turned off his music. She groaned. He couldn't do that, look at her with lusty eyes and do what she told him. It was too much.
She squeezed her eyes shut as she slid her hand into her pajama bottoms, let her hand glid over her wet clit, tried to hold back a sigh as she began to rub her fingers against it. She spread her legs, let her other hand find it’s way down to part her labia as her fingers found a rhythm, rubbing hard circles on the sensitive bundle of nerves. She didn't want to think, didn't want to use her imagination, but it didn't stop her mind from conjuring fantasies, a darkly lit bedroom, hands fisted in sheets and hair, nails digging into skin, and teeth finding purchase on ear lobes and necks.
She tried so hard to keep in vague as she ground up against her fingers, tried to keep faces and distinct features out of it as her free hand slid down to tease its way into her. But then the hair in her fantasy was a mess of unkempt brown fluff, the teeth nipping onto her found a mouth and voice to go with it and the words were teasing and tempting, and the face looking down at hers had dark eyes and red ears. She let out an involuntary moan and half hoped Derek heard it. She shuddered as she fingered herself to completion, thinking about Derek leaning in against her own doorway, grin mocking, eyebrows raised suggestively, normal everyday Derek bringing her over the brink of orgasm, making a wet mess of her hands and underwear.
Too much. She felt too much.