Madison silently cursed herself for deciding to live at home during her freshman year of college instead of the university dorms. When Madison made the decision it was because she didn't want to risk getting stuck with a roommate she didn't get along with, and to save some money; but when she heard her step-brother through the thin walls of her bedroom she regretted the decision. She had been lying in her bed trying to study when the rhythmic sounds of his masturbation started. She tried to convince herself that it wasn't that big of a deal; Nathan was eighteen years old, a high school senior, and all boys his age spent half their days beating off. But when Madison started hearing his aroused moans seep through the wall she got fed up. How was she supposed to get any studying done while listening to her brother grunting like some horny monkey?
Exhaling an irritated breath Madison crawled off her bed and moved for the hallway. Nathan's bedroom door was right next to hers, on the second floor of their parent's split-level suburban home, and she intended to let him know that she could hear everything he was doing. She assumed he locked the door, only meaning to rattle and startle him when she grabbed his bedroom's doorknob, "Nathan! I'm sick of listening to you-"
But when Madison's hand grasped the knob it surprisingly turned and the door opened inwards.
"Madison?!" Nathan yelped, "What are you doing!? Get out of here!"
Madison felt as startled as Nathan looked. She truly didn't mean to invade his privacy in such a manner and had stumbled forward into his room when the door opened. She was treated to the sight of her naked step-brother seated in his swiveling desk chair, erection in hand. Nathan was a tall boy, north of six feet, with short dark hair and his father's bright blue eyes. He had a slender frame with narrow hips; but his arms, legs, and chest carried the compact muscles of youthful athleticism. He was also very tan, Madison noticed, which looked really good on his smooth and hairless body.
Madison started to apologize, "Oh god, Nathan, I'm so sorry! I didn't mean to-"
"Get out!" Nathan screamed.
Madison was initially willing to comply and started backing out of the doorway, but she paused when she saw what was on Nathan's laptop computer screen. He had been masturbating to a picture of her lying on her back by their parent's pool wearing a skimpy bikini.
By the angle of the shot Madison guessed Nathan used a digital camera from his bedroom window, "You perv!" she quickly accused.
Nathan saw what Madison was looking at and reached out to snap his laptop screen shut.
But his action came too late. "You're in here jerking off to pictures of me?!" Madison exclaimed. "You're unbelievable, Nathan!"
"I told you to get out!" Nathan yelled as he reached for a towel and covered his mid-section. "Get out of my room!"
"Wait until your dad finds out about this!" Madison warned as she left the room and pulled Nathan's door shut with a slam.
A second slam echoed through the upstairs hallway as Madison returned to her room and locked her door, fuming over what she had witnessed. She flopped back onto her bed and considered how lucky Nathan was that their parents had gone out for dinner. She didn't really intend on telling them about Nathan masturbating, she only said that to scare him, but if they would've heard what just happened Nathan would have had some explaining to do.
Picking her textbook up Madison attempted to study once more, but as she began reading she thought of Nathan naked in his chair with his erect cock in his hand. Madison couldn't help wonder how big it was, as she hadn't gotten a very good look at it. She guessed it was sizable though, by how much was sticking up from his pumping fist. She had always thought Nathan was attractive, ever since her mom married his dad when Madison was sixteen. There was no denying it; many of Madison's friends often told her how hot they thought her step-brother was.
Even though he was her brother and she had never considered him in a sexual light due to the obvious taboos of such a situation, Madison started to feel strangely aroused. He had obviously been fantasizing about her while masturbating, but why would that suddenly excite her? She imagined Nathan having an orgasm while looking at her photo, picturing him in her mind as his semen shot out and decorated his tanned and smooth torso. That fantasy created a twinge between her legs.
"Get a grip," Madison muttered to herself. She closed her textbook, unable to focus on it, and tried not to think of her step-brother. She had a boyfriend, after all
Madison was pulled from her musings when a knock came on her bedroom door. "Go away," she growled.
"I need to talk to you," Nathan's muffled voice came from the other side.
Madison sighed and moved to sit at the edge of her bed, "You're not naked, are you?"
"Of course not," Nathan called. "Please let me in?"
"Do you have your camera?" Madison asked, unable to keep herself from teasing him a little.
"Come on! Please, Maddy...?"
Madison got up, "All right, all right." When she unlocked her door and let Nathan in he was dressed in a pair of sweats and a tee shirt; she almost felt let down that he wasn't still naked.
"You're not really going to tell my dad about this," Nathan walked into Madison's bedroom, "are you?"
"Of course not," Madison replied, returning to the edge of her bed. She and Nathan may have not always gotten along, but after their parents were married the two had adopted an 'us vs. them' policy and generally kept one another's secrets.
"But you kind of freaked me out," Madison added.
"I'm sorry," Nathan sounded sincere as he sat in Madison's desk chair.
"For what, taking pictures of me in my bikini or for jerking off while looking at them?"
Nathan dropped his forehead to a palm, "Both, I guess."
"Jeezus, Nathan."
"Can't we just forget it happened?" Nathan pleaded.
"Yeah right," Madison scoffed. "Like I can just strike it out of my memory. How many pictures of me do you have, by the way?"
Nathan looked slightly sheepish, "Not that many."
Madison's eyes narrowed, "You don't have any of me naked, do you?"
"Of course not," Nathan sighed, less than thrilled at being interrogated by his sister. "God, I can't believe you caught me masturbating, this is so humiliating."
"Whatever, that part doesn't bother me at all. I mean, you're a guy, all guys jerk off. I'd be more worried if you didn't." Madison felt a little sorry for Nathan, hoping to make him feel less embarrassed, "I masturbate too, you know."
Nathan glanced up, surprised by her admission.
Madison noted, "I'm a little more subtle about it..."
Nathan grinned at that, despite the humbling situation he found himself in.
"But why were you looking at pictures of me?" Madison wondered. "Can't you find any pictures of naked girls online to look at, like a normal guy?"
"Yeah, I look at those too-"
Madison lifted her palm, warning Nathan that he was about to give her too much information.
Nathan sighed, still embarrassed, and decided honesty might be his best path. "You're hot, all right?" he blurted out. "Like, seriously hot."
Madison blinked. Nathan's honesty didn't surprise her nearly as much as the fact that she felt so flattered by his words.
"You're a legend at high school," Nathan continued. "All the guys still talk about you, even though you graduated last year."
