When I first met my niece Karlie, I honestly didn't think much about her. She was just a skinny little girl, about fifteen years old. Jet black hair, big brown eyes, all knees and elbows.
She was my wife's sister's daughter. And she'd come to spend a month or two on the farm with us while her mom and step-father worked out some marital problems they were going through.
Like my wife, Karlie was a Cajun from southern Louisiana. She had the same swarthy complexion and spoke with the same thick accent. She seemed like a good kid, if a little airheaded at times.
It was my wife who first noticed Karlie's crush on me, and brought it to my attention one night as we lay talking in bed. She thought it was cute and had a good laugh over it. I can't say I'd noticed it before then. But I should have.
The girl followed me around everywhere. Feeding the animals, cleaning the pens, coups, and little stable. Working in the vegetable garden and even insisting on going along when I'd hop into my truck to make rounds up and down the fields around dusk to ensure sure my watermelon and cantaloupe crop wasn't being stolen (we have a real big problem with that in Kern County).
Maybe she'd done it before and I'd just never paid attention, but now I became fully aware of Karlie's flirting with me on those drives. She'd laugh and smile and joke, lean into me over and over again or playfully smack my leg or arm.
One drive she complained about the heat (it was really humid) and unbuttoned her top so much her little boobs were nearly hanging out. Each one just a handful and so smooth and white and perfect, I had trouble concentrating on the task at hand.
The second time she did it, she sighed. "I wish I had a chest like Aunt Crystal."
My wife was pretty stacked. Not to sound shallow, but her big tits were the reason I'd initially started dating her when we'd first began going out.
"I just don't think I'm ever gonna get bigger," Karlie pouted, lifting her boobs with a hand beneath each.
"Everybody's different," I said, not knowing what else to say.
"I suppose," she toed the floorboard and screwed up her lips, then she looked at me, smiling. "Do you think my titties look nice, Uncle Beau??"
I laughed nervously. "I don't know that I should be judging that."
She smiled. "It's just a question. Don't be shy. Here, look."
She pulled her top wider open and both of her tits popped out, free for me to look at. I nearly drove us into a ditch and hit the brake.
"Karlie, have you lost your mind??" I growled, dust billowing up around the truck. "I damn near wrecked us."
She shrugged and covered back up. "Sorry. I just wanted an opinion."
I took a deep breath and shook my head. "Yes. You've got real nice breasts, ok??"
She smiled again. "Thanks."
I re-started the truck, it had stalled out and we went home. Later that night in bed, fucking my wife I found myself imagining Karlie in Crystal's place for the first time. As hard as I tried to push the thoughts from my mind, I ended up cumming to the thought of pushing my niece to the ground out in the fields and pinning her down there, while riding her rough and dirty.
When I rolled off Crystal she smiled and smacked my stomach. "Wow. What got into you?? You were really into it tonight."
I tried to avoid Karlie for the next few days, but it proved futile. It didn't help with Crystal practically pushing the girl on me because she thought her "innocent" little crush was so adorable.
The morning Crystal went into town for her annual at the Ob/Gyn and took the truck, leaving me and Karlie both at home, I knew it was going to be trouble.
It was a Sunday and I liked to sleep in a little late Sundays, so after Crystal kissed me on the cheek and headed off down the road for her doctor's office, some 30 miles away, I kept laying in bed. I was naked, only my lower stomach, crotch and one leg covered up by a thin blanket. Early morning sunshine streaming into the room from the windows.
Although my eyes were closed I got that feeling I was being watched. It raised the hairs on the back of my neck, so I opened my eyes and there was Karlie in the extra long t-shirt she slept in, standing at the foot of the bed and staring at my morning hardon. I sat up quickly, bunching the blanket in a pile on top of myself.
"Girl," I snapped. "What the heck are you doing in here??"
"I just wanted to see you," she said, smiling. "Your so handsome Uncle Beau. I like you a lot."
I sighed and ran a hand down my face. "Karlie, I'm forty years old, you ain't but fifteen..."
"I don't care," she said defiantly.
"AND," I raised my voice slightly. "I'm your uncle."
"We ain't blood," she shrugged. "You just married my aunt."
"Exactly," I nodded. "I'm married to your aunt."
"Do you like me, Uncle Beau??" She asked, ignoring my protests.
"I think your a real neat kid," I said.
"No," she shook her head. "Do you LIKE me."
I sighed.
"At night when I hear you up here with aunt Crystal," she took a few steps towards me. "I lay in my bed wishing it was me and you instead."
"Karlie," I looked at her.
"She never has to know," Karlie said. "I ain't telling. It'd just be between you and me."
I didn't speak, just stared at her.
"Please??" She pulled her long night shirt off and dropped it on the floor and stood there naked. Small breasts, flat tummy, bald pussy. As thin and supple as a young willow.
I wanted her too bad to say no. Instead I tossed the blanket back and invited her into the bed.
I took her just the way I'd fantasized. It was rough and aggressive. I kissed her hungrily, licked, nibbled and bit her smooth, warm flesh... working on her neck, shoulders, breasts. I pushed her long legs up over my shoulders and rode her tight little pussy until her moans were nearly screams of mingled pleasure and pain. When I felt myself about to cum, I pulled out and shot my load all over her stomach. I sat there on my knees in bed, sweating and breathing hard. Karlie looked up at me, tears in her eyes but smiling.
"I love you," she said.
"It never happens again," I breathed and finally got out of bed tp walk to the bathroom. "Get on out of here, get cleaned up and dressed. We got critters to feed."

Crystal never found out. Karlie was good on her word. She never so much as hinted at what happened that morning. Although, we did fool around some more before she finally went home. Riding her in the cab of my truck and blowjobs during my nightly rounds became something I started looking forward to. I really missed that little gal once she went home.