Note: This story was dynamically reformatted for online reading convenience. Susan was bored. Alone in the house she sat there trying to think of what to do before deciding to sneak into her geeky step brothers room and browse the net on his computer. Her friend had recently shown her how to access someones web history, and armed with this new knowledge she was curious exactly what Mathew got up to on his hours alone on the web. She felt guilty and nervous as she entered his room, booted his PC up, and tried to remember what her friend had told her. What she found shocked her in more ways than one. Being a girl of a certain age she had discovered the pleasures she could bring to her own body, and had her fair share of fantasies. There was one fantasy in particular however that recently had eclipsed all others, and now looking at her step brothers net history she was shocked to see that she was not alone in what she thought was her unusual tastes. Susan liked spanking. A LOT. It had never crossed her mind that people would bother to write their spanking fantasies down and put them on the web for all to see, and as she started reading one of the stories her step brother had visited she felt nervous butterflies in her stomach and her face became flushed. As she got more and more into the story of a young girl who had been caught smoking by her mother she became more and more aroused. Trembling she scrolled down the page, knowing what was going to happen but still needing to hear how the desperate girl was to be spanked in front of her ogling cousins, she could barely contain herself. At the point she read of the crying girl having to pull her knickers down she finally gave in and let her hand creep under her jogging pants, into her knickers, and onto the small nub of her cliterous. Unknown to Susan, Mathew had entered the house and could hear the tapping of keys coming from his room. Angry that his step-sister would intrude into his private area, he decided to teach her a lesson and crept up the stairs slowly so as to not alert her of his presence. The door was slightly ajar, and with the computer desk facing the wall all he could see was Susan's back as he crept up behind her. 'Ahem' he coughed to give her a fright. His sister almost fell off the chair, and whipped her hand out of her knickers with such a panic that Mathew couldn't help but see what she had been doing. 'Bloody HELL' thought Mathew, and then with shock he saw the story that he had read (twice) the night before on the monitor. He felt immediate panic that Susan had seen what he liked to read, but then realized that clearly they shared the same tastes. 'Erm what were you doing?', he asked his flushed and embarrassed step-sister. Susan decided to bluff it out and try to embarrass Mathew to cover her own embarrassment. 'Just looking at what sites you have visited, you pervert!' Her voice was trembling and she had been tantalizingly close to orgasm when she was interrupted. The guilt of being discovered was written all over her face. 'Well I'm obviously not the only pervert am I!' came Mathew's immediate reply. There were a few seconds of uncomfortable silence as Susan decided what to say next, before concluding that there was no point bluffing any more. 'OK, we're both perverts. I honestly didn't know this sort of stuff existed, how long have you been reading this kind of thing?' On the one hand Mathew was not comfortable talking about something like this to his step-sister, but on the other hand finding out that they shared a common interest was starting to really turn him on. Susan, and Susan's Mother spanking Susan in particular had occupied more than one of his fantasies, and he felt compelled to see where the conversation went. He decided to be honest. 'Well, to be honest I've liked it for a while, something happened a couple of years ago that seemed to push the right buttons for me'. 'Well, what?' replied Susan, although she had a sneaking suspicion of what it may be and knew it had involved her. She was intrigued, and talking about it was starting to re-kindle the fires of her arousal. 'Do you remember a few years ago when your Mom found that you'd faked a sick note to school?' Trembling, knowing what was coming next she said 'Yes' 'Well, when your Mom found out I heard the argument from upstairs and peaked down just in time to see you over your Mom's knee as she pulled your knickers down and started to spank you. I'd never even seen a real life naked bum before, and as Jenny spanked it you wiggled and twisted, I got to see everything!' This was quite a revelation, and Susan was shocked that Mathew would talk about ogling her like this! She felt embarrassed and humiliated that he had seen her naked from behind, but the picture this conjured into her mind only increased her arousal. She paused, took a deep breath and then spurred on by her growing arousal also decided to be honest. 'Well, if you must know I enjoyed it!' Mathew was now so aroused that he became bolder than he had ever been before. Many many times he had wanted to ask Susan about whether she was spanked again and to get as much details as he could so that he could replay the events in his mind when alone later on. 'Has she spanked you since then, does she still spank you now?' burst out of his mouth, desperately wanting her to say yes. 'No, that was the last time .... I guess I've either not been naughty enough or I'm too old. She threatened me about a week ago but I don't know if she would have actually done it' Mathew was disappointed, but not wanting the conversation to end decided to try his luck. 'Well, maybe you should try to get her to do it again?' 'What! you've got to be kidding!' 'Why not? I know the story you were reading, and I know that it involves a girl being spanked by her Mother. I saw what you were doing so I know you liked it, so why not make it happen?' Susan was blushing profusely, but the tingling from her pussy stopped her from just saying no outright. 'And you get to watch presumably?' 'Well, that would be a bonus, would you let me?' she paused as she considered his shocking proposal. 'I still think you're getting more out of this than me' she replied. 'Well, I'll tell you what, if she spanks you in front of me, then you can use my computer whenever you like and I can show you loads and loads of stories like the one you just read.' Her arousal clouding her judgment she reluctantly agreed. 'OK, when Mom comes home and starts cooking, meet me in the lounge and we'll pretend to start an argument. Mom absolutely hates me swearing so I'll swear like mad and we'll see if that does the job.'. 'OK' croaked Mathew, at which point Susan went off to her own room. The time was 5:07, and the next 43 minutes seemed to take an eternity for the 2 of them as they nervously waited separately in their own rooms. Susan plotted exactly how she would get her Mom to spank her, and as she thought more and more about how she hoped it would all play out she became more and more aroused and nervous in equal measures. She was wearing some baggy track suit bottoms and a baggy T-Shirt, and to make what was to be the most blatantly exhibitionist act of her young life even more shocking she decided to put on the shortest T-shirt she owned that didn't even reach her belly button, and then removed her bra to let Mathew see the shape of her small young breasts against the thin material. She was not normally anywhere near as bold as this, and in truth had never even let a boy see her naked before. She was insecure that her breasts were too small and her bottom too plump, but the knowledge that she was about to play out one of her most intense fantasies seemed to override her normally shy nature. Finally her mother arrived home, and she heard Mathew's footsteps as he went down the stairs and into the kitchen. She took a deep breath, then went down to join him. As planned, her Mother was in the kitchen starting dinner for the three of them. Mathew took a sharp intake of breath when he saw Susan. She had pale skin with the slightest freckles and was flushed with nerves. His eyes instinctively flicked down to the shape of her small breasts against the material of her top and his cock twitched with excitement. 'Are you ready?' he whispered 'I'm not sure! this is really really weird!' she whispered back in a nervous voice. 'Come on, don't back out now!' he pleaded Her voice, then half shouting came back: 'Why don't you just FUCK OFF!' Mathew's pulse rocketed as he realized that the game had begun. 'I don't know what you're talking about' he replied. 'you FUCKING SHIT! I HATE YOU!' Susan's mother was shocked at the sudden and unexpected outburst from her daughter, and quickly rushed into the lounge to see what was happening. 'What the HELL is going on?' she said in a very angry and strict voice. 'I am SICK of being treated like a FUCKING CHILD' replied Susan. 'You had better calm down right now or you really will be treated like a child! Now what exactly is the matter?' The implied threat was clear to everyone, and Susan's heart started beating even faster as she anticipated what was going to happen in the next few minutes. 'That CUNT Mathew said that I looked ridiculous in this T-Shirt, and that my tits were like a child's' 'I never said any such thing!' replied Mathew. 'Yes you did you STUPID FUCKER!' This was too much for Susan's Mother, who gave Susan 3 quick slaps to her still covered bottom. 'YOU!' SMACK! 'WILL' SMACK! 'STOP SWEARING' SMACK! Fear, nerves and sexual excitement all tumbled through Susan's mind as she then shouted back 'Oh just FUCK OFF! I am NOT a child! You can't spank me like a little girl you bitch!' This was like a red rag to a bull to Susan's mother who quick as a flash yanked Susan's jogging pants down and while she was still standing gave her 6 more sharp slaps 'HOW DARE YOU!' SPANK! SPANK! SPANK 'Ive got a good mind to spank you properly even if Mathew is here!' SPANK! SPANK! SPANK! This was the moment that Susan had planned for, and with a trembling voice she replied 'Don't you DARE pull my knickers down in front of Mathew you bitch!' Mathew was ready to explode as he watched the drama unfold. Her Mother fell for the bate, and with Mathew standing just feet away yanked Susan's knickers all the way down to her knees exposing her pussy for the first time to her step brother. Every instinct in Susan's body told her to put her hands in front of her crotch to cover her nakedness, but she fought back the urge and kept her hands by her side allowing Mathew an unobstructed view of her naked vagina. With the skimpy T shirt she was wearing, her entire naked form from just over her belly button down to her knees was exposed to his greedy eyes. Mathew drank up the perfectly smooth, slightly plump flesh of his step-sisters body. She had only a thin covering of light brown pubic hair allowing him to see her pussy lips clearly, and he glanced up to the hard points of her nipples through her thin top. He thought he would cum on the spot but held on for the main show. Susan's Mother was baffled as to why her daughter didn't seem mortified by her sudden exposure, but still full of fury sat down on the couch, bent Susan over her knee and began to spank her very very hard SPANK! SPANK! SPANK! 'You will never talk to me like that again!' SPANK! SPANK! SPANK! Mathew was still standing, and didn't really know where to put himself. He stared down at Susan's quickly redenning buttocks, and was shocked to see her legs opening wider as the spanking continued giving him an even clearer view of her pussy. Susan's mother, still spanking her hard then said 'Sit down Mathew I want you to see exactly what happens to naughty girls in this house!' Without saying a word he sat in a seat opposite and blatantly stared at Susan as her spanking continued. What Susan hadn't planned for was that the top was so small and her struggling so severe that it had worked its way up her body. As Mathew watched it finally slipped up over her breasts exposing them for the first time. Her breasts were really very small, but had just enough size to make them bounce with every slap and wriggle. He made eye contact with Susan, who by now was bright red from both shame and arousal. Susan was by now perilously close to orgasm and was desperate to have some privacy to push herself over the edge on her own. She started to plead with her Mother as the spanks continued to rain down. 'OW! OW! Please Mom I'm sorry, I'll never swear again!' SPANK! SPANK! SPANK! 'OK, but if I ever hear you swearing again you'll get EXACTLY the same treatment, now get up!' replied her Mother. Susan slowly got up off her Mothers knees. Again fighting every instinct to cover her nakedness she left her knickers round her knees, and with her T shirt still bunched up over her breasts she turned to he step brother and slowly pulled her top back down and her knickers and track suit bottoms back up. The sight of his petite step sisters entire naked body, her small pale breasts with their light pink nipples so shockingly on display was almost enough to make Mathew cum, and he had to fight the twitches that came from his rock hard erection. She then went upstairs, and her still furious Mother turned round to Mathew and told him to get out of her sight for a while. As soon Susan was back in her room she stripped of her clothes, dived under the covers and started to masturbate replaying the terrible humiliation of being spanked like a child in front of Mathew. Seconds away from climax she heard a knock on her door. Annoyed she answered 'who is it?' 'It's Mathew, can I come in?' Why does he always interrupt me at the wrong moments! she thought, but then pulled the bed sheet up to cover her nakedness and answered 'OK' Mathew entered and nervously asked her if she was OK. 'I'm fine, did you like what you saw? She asked him in a trembling voice' 'Christ Yes! I've never been so horny in my life! She really spanked you hard!' He then hesitated before asking 'Can I see your bum again?' Susan knew where this was going, and holding the thin cotton sheet to her breasts turned over, and laying on her front pulled the sheet off exposing her bright pink buttocks. 'Can I touch them?' asked Mathew 'OK' Susan half whispered Mathew nervously moved his hand to one of her pink cheeks and for the 1st time in his life felt the soft flesh of a naked girl's behind. His cock felt ready to explode as he gently stroked and massaged them, and Susan responded by opening her legs slightly and arching her back up to expose herself to his eager fingers. His fingers moved closer to her pussy, but before touching them he unexpectedly stopped and asked her to turn over onto her back. 'I don't know, I shouldn't really let you see me completely naked like this, I'm not a complete slut you know' 'Please!' asked Mathew. 'OK, but you have to strip off too' she replied. Mathew only hesitated for a moment before stripping off completely and then turning to face his step sister. His cock was engorged and ready to explode, and without saying anything Susan turned onto her back and showed him every inch of her young body. Mathew gazed at her soft white flesh, at her tiny breasts with their light pink nipples, and at the slit of her pussy with its sparse down of pubic hair. He sat down next to her and with a trembling hand cupped one of her naked breasts. 'Touch me between my legs and I'll touch you' she whispered. Both of them were clumsy and inexperienced, but it didn't take long for both of them to bring each other off to a shuddering climax.