All characters are older than 18.
Note to the reader: While you could read it after this one, or not at all, you might find it best to read "Keeping Our 18th Birthday Promise" first.
My brother did a good job describing how it all started in Keeping our 18th birthday Promise. It was wonderful to see how it all felt from his point of view. For this next part though I guess it's my turn to pick up the story.
I know it overlaps a little but I just have to begin with some of our very first time that night of our 21st birthday.
It was indescribable. Well it was, but even so I'll try to describe it anyway.
I could barely contain myself. I'd never had sex. I'd read about it, thought about it, fantasized about it. I was hot, dripping and bent over a hay bale out in the corral waiting for my brother to make it all real for the two of us.
His hands gripped my hips, and after three or four false starts, all at once, there he was, completely and deeply all the way inside me. It was just wonderful. In no time at all he was moving all around in there and it all felt fantastic.
We were both so excited it was over in no time at all with a spasm like nothing I'd ever felt as I came suddenly and felt him empty himself inside me.
Of course then we found mom and dad had seen the whole thing. Even more, before my brother and I spent our first night together as a couple they had a real surprise for us. After some time back at the house sort of celebrating with them I found myself back out in the corral bent over my naked mother. I was sucking her tits while she fondled mine and and my brother brought us both to a very messy amazing climax. Dad also made it clear he expected his turn to do the same with us both later when they got back from their vacation. And wasn't that something to look forward to?
My brother and I had more good old fashioned baby making sex on and off till dawn that first night. Mom and dad took off in the morning for what was supposed to be a month long vacation and at last the place was all ours.
We got busy the next day setting our plans in motion for turning the farm into a real business. Of course we also spent a lot of time discovering one another as lovers.
I'd started ovulating the previous morning and he kept me full of his seed pretty much every day that first week. I really truly wanted to get pregnant. I was also really looking forward to dad doing mom and me together when they got back. Getting myself pregnant seemed the most pleasantly practical way to make it safe for that to happen too.
So at the end of that first week there I sat in the bathroom, early in the morning, full of butterflies and hope. When I flipped it over to look the home pregnancy test I'd just taken was, negative. Goodness knew it sure wasn't for lack of trying. Disappointment didn't last too long however. I told myself it just meant I got to keep trying. I mean we had the whole rest of the month.
I mentioned the negative test over breakfast. With a sympathetic look my brother said not to worry too much. He'd learned while getting his agriculture degree how to figure the odds on insemination. I guess I must have looked a little puzzled because with a small grin and a chuckle he said, "It's a basic probability calculation. Given the chances of success on a single try while a female is in heat and the number of times we've been at it our odds this week were at best about 70 percent."
"You can actually figure that out?" I asked.
"Sure," he replied, "but it also means there was at least a 30 percent chance it wouldn't take as well."
"Well then at that rate it's almost certain I'll be expecting by the end of this next week then," I chirped happily.
His smile drooped and he shook his head slowly. Taking my hand he said, "Sis, it's not quite that simple."
At my crestfallen look he gently squeezed my hand and continued with, "Those odds are only while ovulating and you're almost certainly pretty well past that at this point. While it's not impossible it could happen before your next period it's not really too likely. Of course I'll be happy to keep screwing you every chance you give me just in case but I think you're going to have to wait till next time to really get your hopes up again."
"Well okay," I sighed.
"Hey it just takes time and trying sis."
"I know. I'd just hoped I'd be up for having dad take mom and me like you did without any worry of his being the one to nail me."
He just laughed and said, "I thought you knew. Dad got snipped not long after mom was pregnant with the two of us sis. He's completely safe. See? No worries."
Well that was one load off my mind but I still wanted to get pregnant. I handed him a mid morning snack in a brown paper sack before he headed out to start brush hogging a large field before he tried to plow it. We wanted to get prepared for setting up a corn maze to plant in the spring for some fall fun.
When I got back from town a couple of hours later from seeing various suppliers and contractors about our bed and breakfast conversion plans I could hear the tractor still working away in the field behind the barn.
It was pretty warm so I skipped the underclothes and put on a very loose cotton blouse and nice roomy shorts before going out to work in the kitchen garden. I had always enjoyed keeping it in shape and needed to do some weeding and a bit of fertilizing for a few of the plants.
The sun was warm on my back as I knelt. The light breeze was blowing into that loose blouse from behind. It caressed my tits where they hung down inside and I could feel the fabric of my shorts stretched nicely across my upraised hips. I was thinking of nothing in particular when I heard my brother say, "Wow sis. Seeing you there like that sure makes me want to work on a furrow in someone's garden. Maybe do some plowing and planting. What do you think?"
I thought it sounded like a great idea. I stood and turned to find him stepping out of his pants right there in the garden in broad daylight.
"Right here?" I asked.
"Right now," he replied with a huge grin.
"No sooner said than done," I thought and shucked my clothes. Oh but the sun felt warm as it shone on me. I walked up and gave him a big hug. For his part he grabbed my butt and lifted me.
I felt his erection as it slid past my slit on the way up. I really felt it when he slid me back down all the way over it. Oh my but that was nice. With a wiggle to fully seat myself on him I wrapped my legs around his back and locked my ankles above his hips.
That got a gasp of breath from him. I just mashed my breasts against his chest and let the feelings wash through me as he pumped away.