Incest Stories Site

Incest Stories for everybody

The Bet

by TheMoose63

Caution: This story contains strong incestuous element of sex between siblings.


He had won and she had lost and that was the bottom line. Initially it had just been an argument between siblings but it ultimately turned into a bet over their grade point averages. His sister bet that she would end up with the higher GPA and she had lost, 3.9 to 3.87... it was close but still she had lost.

When they had first argued over their GPA's it had just been for fun then his sister taunted him about her being smarter and Mark caved in and agreed to the bet. Mark had at first been hesitant to agree with his sister because she was so damned smart but when she had said that she would do 'anything' he wanted, assuming he won of course, he had smiled and then agreed and they sat down and hammered out the details. Mark still remembered the conversation like it was yesterday although it had been almost nine months ago...

"I'll tell you something Mr. Jockstrap," Caroline said to her brother, "I'll be standing behind the podium as the class valedictorian and you'll be listening to my speech with the rest of the crowd out in the audience."

"Bull, I can beat you in a heartbeat!" He didn't really believe that but he couldn't back down now!

"Really? Well I'll tell you what brother; if you beat me I'll do anything you want."

Mark cocked his head and thought about her offer. "Hummm... anything... alright sis what exactly are you offering?"

Caroline was positive that she was going to win so she offered what she knew would intrigue him the most. "I'll put myself on the line here Mark; I'll do anything your little perverted mind can conjure up short of having sex with you although I'll bet that already crossed your dirty little mind."

It had, but Mark shot right back with his counter offer. "Alright smart ass, no sex but here's my deal, take it or leave it. If I win I want you to give me a hand job and I want you to do it with nothing on but your bra and panties... if you win I'll clean our new apartment up at college for six months... deal?"

Caroline thought about his proposal and was anxious to agree, after all she was the brains in the family and Mark was the jock... although he did have pretty good grades too..."Alright it's a bet but if I win you'll not only be cleaning our apartment for six months but you'll do it in nothing but your underwear... and I can invite people over to watch you... deal?"

"Deal!" They sealed their wager with a toast of their sodas.

Nine months later, on the second of June, their respective report cards arrived in the mail and the contest was over, well almost over, Caroline still had to pay off the bet.

After they had compared grades she looked at the brother. "Look Mark," she cooed in her sexiest voice, "you aren't really going to make me do this are you; I mean its sick for Christ's sake, and besides you're my brother!"

Mark just smiled at his sibling. "Sorry sis it may be sick but I've worked the whole year just for this moment, now it's time for you to pay up!"

That Saturday night their parents left for a bridge game at the Henderson's and Caroline and Matt were finally all alone. They watched as their parents drove off then Matt turned to his sister and leered. "Well sis, are you ready?"

Caroline sadly shook her head knowing that pay up time was here and there was no way out. "Alright, let's get this over with."

Mark smiled and headed up the stairs. "I'm going to take a shower; I'll meet you in mom and dads room."

Caroline crooked her head. "Mom's bedroom... why there?"

"You'll find out." Mark went into his bedroom and stripped out of his clothes then went into the bathroom and stepped into the shower. Mark was a decent athlete playing second-string linebacker on the football team and third base during spring baseball. He stood 6' 2" and weighed just over 175 pounds and was considered a 'good guy' by most of the high school girls... still, although no one knew it, he was a virgin. Mark had consciously abstained from sex while in high school, mostly because he was concerned about catching an STD but he was even more concerned about getting a girl pregnant. He adjusted the water and lathered up his body paying special attention to his cock. He knew that if his sister jack him off right now he would cum too quickly and that was the last thing he wanted, he wanted his session with Caroline to last for a long time. That morning he had masturbated using an image of his sister jacking him off to cum and now he leaned against the shower wall and jacked off again this time thinking about his mother and pretending that she was blowing him. He had often used his mother as a sexual fantasy mostly because she looked so much like his sister and today her image worked just like it always did as his cock spurted rope after rope of cum on the shower floor.

There was a voice from out in the hallway. "Hey... what's taking you so long, you're not jacking off are you? You better not be!" Caroline yelled through the closed door.

"I'll be right there sis." He turned off the water and grabbed his towel and dried off then donned a terry cloth robe and walked across the hall and into their parents' bedroom. Caroline was already in the room, standing by the end of the bed in a pair of shorts and a blouse.

Caroline watched as her brother entered the bedroom and she could see the small bulge in the front of the bathrobe. Although she had dated since her sophomore year she had never gone any farther than light petting, letting one boy touch her breasts and suck on her nipples and then in her senior year Jim Hauser had managed to slip his hand underneath her dress and inside her panties where he rubbed her clit until she came. After her climax she lay back against the backdoor of the car panting, her breathing labored and watched as Jim started taking off his pants. When his pants hit the car floor she panicked knowing he expected the same treatment he had just given her. Caroline grabbed the door handle and flung it open and raced into the house and that was a close to having sex as she had come.

Mark looked at his sister and her far away gaze. "What are you thinking about sis?"

"Huh... oh nothing... why?"

"You look like your mind is miles away."

"No I'm right here and ready to pay off, now why are we in mom and dad's bedroom?"

"You'll see." Mark walked over to his mom's closet and opened the door and went inside and rummaged through her dirty laundry hamper until he found what he was looking for, a pair of her dirty panties. He grabbed them and balled them into his fist so that they weren't visible then he walked back over to the bed, stripped off his robe and, his cock already getting hard as his sister watched him, he hopped up onto the bed and waited for her to get undressed too.

Caroline sighed and then walked over to the side of the bed and sat down next to her brother and looked down at his cock. It was a lot bigger than she had thought it would be, maybe six inches or so and really thick. She started to reach for him but he stopped her, grabbing her by the wrist.

"Oh no you don't! You agreed to do this in your bra and panties so strip sis."

Caroline took a deep breath then shrugged her shoulder and began to unbutton her blouse. She was a pretty girl, not beautiful but she had never lacked for male attention. Her breasts weren't as big as her mother's but she did have a respectable 34B bust line. Her blouse off she unbuttoned her shorts and as she started to slide them over her butt she remembered that she was wearing a pair of bright red French cut thongs and wished that she had worn something more sensible like a pair of plain white cotton granny panties. Oh well she thought as she pushed her shorts down and stepped out of them and then crawled up onto the bed next to her brother.

Mark looked at her appreciatively. "Geeze sis you've got a great butt!"

Caroline looked down at her smiling sibling and smiled back. "Well thanks, I appreciate the compliment and you've got a nice looking cock. I guess that's why Mary Ann likes to get you alone in her bedroom."

Mark looked up confused. "Mary Ann? Mary Ann Barnes told you that we had sex?"

"Yup, one day after gym class she confessed everything."

"Well I don't want to burst your bubble sis but I've never had sex with anyone and especially not with Mary Ann... Christ she's a total slut. You think I want to dip my dick into that and catch God knows what?"

"So you're... you're a virgin?" She asked incredulously.

"Sure am... I've been very careful to not contract some ugly disease and I sure as the hell didn't want to get some girl pregnant... how about you, you having sex with anyone I know?"

"NO! What do you think I am some kind of a slut?" She looked mad then changed the subject. "Now tell me what's in your fist and why are we in mom and dad's bedroom?"

He opened his fist and revealed his mother's panties. "They're moms' panties and I love the smell she gives off. Whenever I can I sneak in here and steal a pair of her panties to smell when I jack off. See, I thought that while you play with my cock I would think about mom."

"Yuk! Brother you are some kind of fucking perverted... smelling moms' crotch."

He put the panties up to his nose and inhaled. "Ummmm, well go on and get started sis."

Caroline shook her head as she watched him smelling the panties. She reached out and lightly touched his cock and was surprised at how warm and big he was. She could barely wrap her hand around his shaft but she grabbed him and started the traditional rapid up and down movement.

"Stop! Jesus Christ what are you doing?" Mark yelled.

"What? What's wrong?"

"That's way too hard. Christ sis how would you like it if I grabbed your tit and squeezed as hard as I could?"

"Oh... I'm sorry but what do you expect... I've never done this before."

He looked up at her in amazement. "Okay... well just take it easy and for Christ's sakes be gently. Look you have to start slowly and then build up until you're going faster and faster. Just watch me and I think you know how I'm doing... and when I'm close to coming."

"Alright but you have to let me know if I'm doing it right." She took his cock into her fingers and this time she gently jacked him off. She was fascinated by his cock and how it reacted to her touch. Although he was hard his skin was still soft and warm and every time her hand went over his ridgeline he moaned with pleasure. She watched him as he had asked and saw the signs of pleasure... his butt lifting up to meet her hand, the arching of his shoulders and she knew he was enjoying what she was doing because that was the way she acted when she masturbated. "How's that feel?"

He pulled his mother's panties away from his nose and watched as his sister slowly jacked him off. "It feels great sis, keep it up."

"Thanks." She kept sliding her hand up and down but she was getting excited too. She could feel the dampness in her pussy and she let her fingers trail across his chest, touching his nipples.

"Oh my God Caroline... that... that feels..." He opened his eyes and looked across at his sister and smiled then he noticed the wet spot on her panties. Christ, he thought, she's getting turned on too.

"Mark?" She squeaked.

"Un huh."

"Why are you so infatuated with mom? I mean smelling her panties, jacking off thinking about her, what's up with that?"

He reached down and took her by the wrist and stopped what she was doing. He got up onto one elbow and stared at his sister... thinking, then he finally decided to admit why. "Don't be mad but it's because mom is a perfect image of you... only she's older and I didn't think jacking off with my sister's panties was a good idea."

"Me! You really wanted to think about me when you jacked off?"

He lowered his eyes and started to get off the bed. "I'm sorry sis... go on and get out of here your bets been repaid."

"Mark... wait!"

He turned back and looked at his sister and saw her taking off her bra. "Caroline, what are you doing?"

"Well as long as you've admitted that I'm your sexual fantasy I have to admit that I've masturbated thinking about you too." She slipped off her now very damp panties and tossed them to him. "There you go bro, sniff them and tell me what you think."

He looked at his sister, holding her panties in his hand. God but she was gorgeous! Her pert breast, her hard little brown nipple sticking straight out from her half-dollar sized aureoles and then his gaze fell between her legs. She had light brown hair that was mated just a bit from her wetness but he could easily see her labia. He brought the panties up to his nose and inhaled her scent. "God Caroline you smell great."

I thought you might think that." She lay back on the bed and spread her legs apart. "Go on Mark, I want you to taste me."

Mark got onto his hands and knees and bent forward letting his tongue slip inside his sisters' virgin pussy. He licked up and down on her labia then his tongue touched her clit and she jumped.

"Oh yes! Oh God Mark, do that again."

He licked and suck on her pussy until she came. Her hips jerked violently, thrusting up into his face, her legs wrapped around his neck then she lay back panting. "Now... now my sweet brother I'm going to take care of you. Any chance you have a rubber?"

Mark was surprised by her offer. "I know where dads are." He reached over and opened the top drawer on the bedside table and pulled out a rubber.

"Here Mark; let me put that on for you." She took the tinfoil package from his hands and opened it and took out the rubber and slid it over the top of his cock then rolled it down until it covered his hard on. Okay now let's do this before I chicken out and change my mind."

"Caroline? Are you sure you want to do this? I mean when you told me you were still a virgin I figured you were saving yourself for marriage."

She hugged him then kissed his cheek. "Yes I'm sure silly... after all what could be better than loosing your virginity to someone that really, and I mean really, loves you?"

Mark got between her legs, held his cock at the entrance to her womanhood. He looked at Caroline then slowly entered her until he came to what he presumed what her hymen. "I heard that this might hurt sis, are you ready?"

"Yes... just do it!" And it did hurt, it hurt a lot but then the pain changed to euphoria as Mark's cock pistoned in and out of her pussy. Wave after wave of pleasure overtook her and she had one climax after another. "Oh God Mark that feels so damned good."

He loved the feeling of fucking her. As his cock slid in and out he could feel the tightness on his cock then there was the warmth of her breasts pressed into his chest. God things didn't get better than this... then they did as his cock twitched and he came, his cum filling the rubber almost to bursting. He collapsed onto her chest breathing rapidly. "Oh my God Caroline... that was great."

Of course the sex really wasn't all that great but they didn't know it after all they were both virgins. But it got a lot better the following year when they shared an apartment near the state college campus. It wasn't all that unusual for siblings to share an apartment while they were in college and the best part was that the rent was being paid for by their parents. Even funnier was the advice they had received from their parents before they departed for school.

His father had taken him aside downstairs while their mother spoke to Caroline in her bedroom.

"Look Mark, you go to college and study hard but have some fun too, but not too much. I don't want you screwing every piece of ass that comes along and that's why mom and I are paying for you and your sister to share an apartment... after all you can't exactly screw the whole campus with your sister right there."

Upstairs in the master bedroom her mother handed Caroline a prescription. "Here you go honey, it for birth control pills. I know how girls can be while they're away at college and you certainly don't want to get pregnant. Beside that's why your father and I are paying for an apartment... to make sure you don't have too many boys over."

Three days later Caroline and Mark looked around their new apartment then opened a bottle of cheap Champaign and toasted their new found freedom. "To the love of my life!" She said as she hugged him.

"I love you sis!" He said then kissed her.

"I love you too bro, now let's get out of those clothes and check out the bedroom!"