All characters are over the age of consent .
*****
My brother Tom and I were in the same high school but we had to leave it because of dad traveling a lot and we did a lot of relocating. So, for our last year in high school, mom home schooled us.
Mom used to be a teacher but gave it up when she married dad so she was familiar with the education system and it actually made our lives easier.
Dad was on the tail end of one of his extended trips and would be home soon as mom started teaching us, getting us ready for our final year and graduation.
By the way, my name is Tiffany. I just turned eighteen and I am 5'6", 110 pounds, average sized boobs and Tom says I am fairly attractive, or as he says, he wouldn't throw me out of his bed.
Tom is nineteen, being a few months older than I am. He is tall, about 5'11", 165, and has a nice build as he played high school sports. Oh yeah, he has a nice big, fat cock that I saw once when he was jerking off and he did not see me watching.
We now lived in Nevada where it was constantly hot and not conducive to outdoor activities. Although we had air conditioning, the heat was still oppressive.
Mom and Dad set up a room for us, like our own classroom, so we had the feeling of being in school.
Classes started at 8:30 a.m. and finished at 4:30 p.m., with an hour for lunch. The curriculum was set and all Tom and I had to do was learn and pass the tests.
Mom told us that dressing was optional, meaning we could wear whatever we wanted and as little as we wanted.
For the first couple of months classes went well and we adapted to being taught at home.
On more than one time, I went to class topless, which was no big deal because mom had seen me parading around nude or semi nude all the time. And besides, I knew it would get Tom aroused and I loved to see his hard cock straining to be free.
However, when our Biology classes started, things got interesting. Mom believed in practical experiences and would have us come to Biology classes naked. She also taught us naked for the Biology classes.
Tom and I used to talk about mom being nude and Tom told me that he would love to fuck her sometime. Hell, I even told him that I would not mind playing a bit with her myself.
Now, Tom and I are not prudes and we have seen mom and dad naked before and they have seen us, even as young adults, but it still seemed strange having our naked mom teaching us.
However, we got over it and learned to love going to Biology classes. I enjoyed watching Tom's cock come alive when we were in class.
Today's Biology subject was going to be interesting. Mom was going to teach us about reproduction.
Tom and I were a little uneasy about this class because we had no idea what mom had planned. In any case, Tom and I showed up naked and ready for almost anything.
Class started as usual. Mom was naked and I could see her nipples were a little erect so I figured mom must have pleasured herself before class and it was no big deal.
Mom asked us about reproducing and Tom and I told her we knew how it happened and how babies were conceived.
Mom asked us both if we had any practical experience, meaning did we fuck anyone yet. Tom said that he didn't actually get that far with a girl but that he did cum when the girl sucked him
I told mom that I did not have any practical experience but, that I have seen several soft and hard cocks.
She then said that today, Tom and I would learn first hand about reproduction.
Mom moved the class to her bedroom. She told me to sit on the chair and watch.
Mom got on the bed and told Tom to join her. I could see that Tom was getting aroused as his cock was twitching as it got harder. Soon, Tom's cock was fully erect. He laid next to my mom as she started giving him directions.
First, mom said, sex is beautiful and must be done right, even if you are not trying to reproduce. She said that a man and a woman must make love, not just fuck. She then said she would show us both and for me to watch her and Tom first.
Mom pulled Tom to her, his chest pressing against her tits. His cock was pressing against her stomach. She told him to kiss her and, as he was kissing her to move his hands over her body, feeling her tits and nipples to get her excited and ready for his cock to enter her cunt.
Tom seemed to be a fast learner because mom was doing a little moaning as Tom played with her. I could even see mom open her mouth and Tom putting his tongue in it.
I looked down at mom's smooth pussy and I saw that her thigh was wet. Tom moved his hand down to her pussy and started playing with it. Then mom told him to put his finger in her cunt so that she would be very wet and ready for his big cock.
Tom put more than his finger in mom. He moved his mouth down to her pussy and slipped his tongue in her.
Mom told him he was doing a great job and was a quick learner.
Mom told Tom to get on top of her and, as he did, she grabbed his big cock and placed it right at her slit. I watched as mom opened up her lips and guided Tom's cock into her until it could not go in any further.
Mom told Tom to start pumping his hard cock into her, slowly at first then to pick up the pace.
Soon Tom was fucking mom real good and it didn't take long before he told mom that he was cumming. Mom told him to pull his cock out and to cum on her tits as she wanted me to see Tom cum.
Tom pulled out his cock and shot his cum all over mom until he was finished.
Then mom told me that after lunch and Tom has rested, it would be my turn to learn.
As we were having lunch, dad came home and saw us having lunch naked. He asked mom what was going on and she explained to him that she was giving a Biology class on reproduction and she wanted us to learn first hand. Dad said he would like to join the class as soon as he showered.
As lunch finished, the three of us went back into the bedroom. Dad joined us and was naked like us. I saw dad's cock which looked much bigger than Tom's, now that it was hard. I could only imagine his cock fitting into my tight cunt.
Mom and Tom sat on the chair and told me and dad to get on the bed. She told me to make love to her dad like Tom did to me.
I pulled my dad close to me, my tits pressing against his chest. Dad kissed me on my lips and I instinctively opened my mouth to let his tongue meet mine. I could feel dad's hands all over my body as our bodies pressed against each other. I could feel his hard cock pressing against me.
Mom then told me to move my mouth down to my dad's cock and to suck it. I followed mom's direction and slipped my mouth over dad's cock head and was soon running my mouth and tongue over his cock shaft. Dad must have liked it because he was moving his cock into my mouth as I was sucking it, almost like he was fucking my mouth.
I heard Tom saying that I could do that for him anytime as I continued sucking my dad. I told mom that I felt some wetness coming from my dad's cock and she said it was precum and that I was doing a great job. Then mom asked if my cunt was wet and I said it was. She then told me to let dad mount me and for me to spread my legs wide.
Dad mounted me and my legs were spread for him. He took his hard cock and placed it in front of my slit like mom did with Tom. Soon, I could feel dad's cock entering my hole and stretching me as he started to fill me up. A couple of thrusts and my dad had his cock inside me completely. Mom told me to relax a moment and that dad will start to fuck me like Tom did to her and for me to enjoy it.
Dad looked down at me and asked if I was ready to get fucked and all I could say was yes, daddy. He started pumping me slowly, drawing his cock almost out of me then pushing it back in. Soon, I started fucking my dad back. I loved the feeling of his cock filling me up. After a few more thrusts, dad said he was going to cum.
Mom told dad to cum in me so Tom could see the way reproduction was. Dad obliged mom, and shot his cum into me as I fucked his cock as he was spurting his cum in me. Finally dad stopped cumming and his soft cock slipped out of me.
Mom then told me to lick dad's cock and get all his cum off of it, which I did.
Mom said I did an excellent job and was a real fast learner. She then said that after dinner, Tom and I would be fucking each other to make sure we learned everything from class.
As Tom and I were leaving the bedroom, mom got on the bed with dad and started to fuck. Tom and I asked if we could watch and they said it was ok, so we watched until dad came.