David had been working on his latest invention for three months and was stuck. Every time he tested it on his mice all they wanted to do was copulate. He was trying to get them to reduce their intake of food. He didn't even have to turn it on any more, the mice were always screwing, it was as if they were now programmed to do that all the time.
"Dammit, here I was trying to make a way of changing a person's attitude and all I came up with is an electronic aphrodisiac. Holy Shit, why didn't I see this before, HOLY SHIT. I have to find out if it works on people. Who can I use to try this on? Its' just me and Lynn and mom in the house. First things first, I have to make this device portable."
His mind switched to double time. He began envisioning modifications in his circuitry he could see the whole thing in his head. Then as he started to build it he saw ways of reducing the size even more while at the same time increasing the power thus increasing its' field of effectiveness. He even had a way of turning it on and off by remote control. After a few weeks he had the whole thing finished. The only thing left was to try it on a human. Then several weeks later he was once again alone in the house with his sister Lynn. David was down in the basement making sure his Device was working properly, Lynn called down to him from the top of the basement stairs.
"David, I have Gym practice in a few hours so I ordered pizza for us to save some time. Come up now, please, or it will get cold."
Lynn was his nineteen year old sister. While David was just turning eighteen. She was petite with a perfectly proportioned body. She had dark brown hair and emerald green eyes. David had yet to see anyone with eyes like his sister Lynn. They made her startlingly beautiful. With her gymnastic ability she was picked as first alternate for the Olympic gymnastics team. She really should have won easily but a week before the tryouts an accident caused her to hurt her ankle . Her dismount from the beam caused her to lose a point and that was all it took . She lost by one, one hundredth of a point. David was graduating with her and both had several scholarship offers. One school to which they both had scholarship offers was the UC at San Jose only 70 miles from home. The school offered excellent courses in Biology for Lynn, because she wanted to get a doctorate in physiotherapy and for David, he wanted degrees in electrical engineering and biochemistry.
"Listen up guys, if you go to San Jose it won't cost a cent because of the scholarships and this way you can room together and I'll feel better that you can watch each other's backs."
Lynn really couldn't argue because she liked her brother and got along with him very well. While David, liked his sister and easily got along with her. So it was agreed that, that's where they would go.
Julia their mother acted as though she had to watch every penny. In reality she was a very rich woman. Why she acted as if she had to be so very careful about money she didn't know. If she had to announce how much she was worth it would be many millions of dollars.
"What kind did you get?"
"I got a large pizza, half plain with extra cheese and the other half with mushrooms, sausage, onions and olives."
His sister was wearing her bathrobe and had her hair wrapped in a towel.
"How come you took a shower now if you are going to the gym in a couple of hours."
"I just wanted to test my ankle so I did about 45 minutes of aerobics. Anyway, I must be all healed, because there was no pain at all. Why do you have your book bag with you?"
"That's good, I'm glad you are all healed. As for my book bag I'm going to call Pauly and see if he wants to go over some electrical circuits I designed.
David turned the Device on. He could tell it was working because he felt that tingle in the tips of his fingers and in his earlobes. His sister started to shift around in her seat. As if she was trying to find a more comfortable position.
"I don't know what's wrong with me? For the last few days I have been feeling so strange. Like I really need something, This is the strongest I have felt it. Oh god, I feel so weird I.....I.....
Lynn reached inside her robe and was massaged her breasts. As she moved her hands down her body her robe fell open as she rubbed her groin. Both of her breasts were exposed to him and a flush spread across her chest and neck.
"I have to go up to my room. Please help me."
As David touched her to help her up, the sensation got ten times worse.
"Help me David I need it."
"What, what, do you need?"
Lynn reached down and cupped his groin.
"This. This is what I want."
David was amazed. He never expected anything like this. His sister was so turned on he was shocked. She began to fumble with his belt and when she got it open she started on the button at his waist. When she got that open she pull his zipper down and open. His jeans fell down around his ankles. Lynn threw her arms around his neck and she began reigning kisses all over his face and finally his mouth. David tried to take a step back but with his feet entangled in his jeans all he succeeded in doing was to fall back hard on his ass, with his sister on top of him. When he tried to speak Lynn pushed her tongue into his mouth to duel with his tongue and caress the roof of his mouth. Somehow she had gotten her robe off and now she was completely naked, her arms and legs wrapped around him, holding him tight.
"I need it. I need it so bad. Let me have it baby. Please. I'll do anything you want. Anything. Give it to me Davy. Please baby."
She had his boxers down too and was pulling on his stiff dick. She was trying to stuff it inside her pussy.
"Give it to me, god dam it. I need it so bad. Please. I told you I'll do anything you want."
He rolled her over trying to get her off him. All he succeeded in doing was to make it worse. The head of his cock was inside her. He didn't want to fuck his sister. She was his sister for god's sakes. He was thinking god she's strong. It has got to be from her gymnastics. She was forcing him deeper inside her with her legs. He could feel some sort of barrier blocking his further entrance. He suddenly realized this was her hymen and he knew for certain she was a virgin. All of a sudden it was gone and he was hilted deep inside of her. Lynn was humping against him and it felt so good to be deep inside her. His body responded automatically he began a slow rhythm of thrusts inside her. It felt even better moving like this.
"Oh, that's so good, Davy. Do it faster and harder. Oh god, I'm going to cum I.........AAAHHHH AAAHHHH AAAHHHH."
David fucked her for the better part of another forty five minutes. In the missionary position, the doggy position, cowgirl position, reverse cowgirl position, bent over the table, bent over the back of the couch, in the easy chair, every possible way he could think of. Lynn loved it all and wanted more. They were sitting in the easy chair with her on his lap and she was making cooing noises. He suddenly realized the device was sill firing. He could still feel the tingle in his fingertips.
"Oh, shit. It's still on."
David didn't know it yet but he had irreversibly programmed his sister to be his sex slave and she would be so, for the rest of her life.
"What is still on Master?"
"Why are you calling me Master?"
"I belong to you now Master. I felt you change me Master."
"OMIGOD, what have I done."
"Don't be sad Master. Now, we can do this whenever you want. I love you. I'll love you for the rest of my life. I belong to you now."
"Wait a minute, I have to check something, stay right here and don't move."
He picked her up and sat her back in the chair. He found his shirt lying on the floor, in the pocket was the remote. With a flick of his thumb he turned the remote off. He ran down to the basement. He had put the mice out of the way on the other side of the basement. When he looked into their cages they were happily fucking away. He thought, Jesus, it's true they haven't been exposed to the Device for a while and they are still acting in the same way. He went back upstairs he looked like he was about to cry.
"Don't be sad Master, I'm very happy you made me your slave."
"Oh god Lynn I'm so sorry. I didn't mean to turn you into a slave."
"That's alright Master. I like being your slave. After my period you can try again to make me pregnant. It's too late to make me pregnant this time but we can try again right after my period."
