Kenzie

Her eyes got wide, and her mouth, already poised in a slight smile of arousal, opened up to reveal bright white teeth. "Do you... do you mean it, big brother?"

I nodded. "I'm yours to command, Kenzie."

"All right!" I'd never seen her face with such an expression of complete happiness as in that moment. She wrapped her arms around my waist, and pushed off with her hips so that we rolled over, stopping with her on top of me. "I guess you're right," she said, her full voice back in her throat for the first time since the living room. "I'm the man in this relationship. And you, big brother, belong to me!"

That wide white grin never slipped from her face as she sat up and unbuckled my jeans. She clearly didn't know exactly where my hips would be, because it took her a couple of tries to yank them down, but when she did, she looked at my underwear and drew back in surprise. "Oh my God, Neil, you... you are sopping wet!"

"Is that good or bad?" I asked, though I already knew the answer.

"Oh, it's definitely good." She had a look on her face like a fox that was about to pounce on a particularly juicy hen. She pulled my underwear down past my knees, and without a moment's hesitation, buried her face right in my new pussy.

Okay, yeah, I know that I said that word sounds cheap, but in that moment, it was definitely the right word.

Her tongue lapped out and circled my clit, making rapid patterns around my lips. She didn't quite stick her tongue all the way in me, but she was definitely tracking all the spots that had the most intense nerve endings. I always thought my cunnilingus game was pretty good, if I can say that without bragging, but she was finding spots that I never previously knew existed.

I didn't know what else to do while Kenzie was tonguing me to a new peak, so I just reached up and grabbed a couple of fistfuls of her hair. For six years now, I had wanted to play with my sister's beautiful black hair, but now that I had the actual chance, her tongue was putting such new feelings into me that I almost forgot what hair even was.

"Oh God, Kenzie," I moaned, struggling for breath. "You're going to make me cum."

"Not yet I'm not," she said, finally letting my snatch go. She sat up on top of me and grinned. "That was just the warm-up."

I watched her unbutton her jean shorts and push them down. She twisted around to slide first one leg out, then the other, sinuous like a dancer en pointe. Watching my sister kick off first her shorts, then her underwear for me, I felt my heart literally skip a beat, and I wondered if I was going to die in the throes of passion with Kenzie, the most beautiful girl in my world.

Once she was naked from the waist down, she pointed both index fingers down at her own groin. "Does this look familiar, Neil?"

I looked where she was pointing, and I definitely recognized what I saw, though I had never seen it from this angle before. "Yep," I said, "that's definitely my cock."

Kenzie nodded. "I thought that pussy looked familiar when I was down in it. We did indeed swap straight across, big brother." Then she chuckled slightly. "I'm about to fuck my own pussy."

"Well yeah," I said, "I'm about to get fucked with my own cock."

We both chuckled, then Kenzie seemed to hesitate. "If we do this," she said, "we can never undo it. You know that, right? Even if we never fuck again, we can never go back to being a brother and sister who have never fucked. No matter what happens, we will never be completely normal again."

"Kenzie," I said, "I haven't felt completely normal since the day I first looked at you and felt lust in my heart. I thought I was a freak for wanting you. My own baby sister! Now I realize the only think wrong with me was that I didn't ask for this sooner. Now hurry up, I need to feel you inside me!"

She smiled at that, then shifted so that she had her cock pointed directly at my opening. "I just needed you to say it, big brother," she said, and in one swift motion, she entered me.

Like I say, neither of us were exactly virgins. I've been with plenty of girls before. But there always felt like some kind of mismatch, as though our bodies didn't fit quite right together. Even at the most powerful and loving, I always thought something felt off.

Not this time. Kenzie's cock fit smoothly into my snatch, as perfect as a key in a lock. It felt like our bodies were made for this moment.

Clearly Kenzie felt something too, because she got this astonished look on her face as she began to move in and out of me. "Oh God," she whispered, "I'm fucking my big brother. Oh Neil, you feel so right. You and me, oh, oh, we're perfect. I'm fucking my big brother." She moved inside me with smoothness and confidence, with the strength and purpose of someone who definitely belonged there. "I'm fucking my big brother. Oh God."

Then she hesitated, her rhythm slowing down, as she said, her voice heavy with realization:

"I'm fucking you without a condom."

"Don't you dare stop," I said, grabbing her hips. "This is the only thing I want, and don't you dare take it away from me."

"But what if... what if..."

"Worry about that when the time comes," I said. "Right now you need to keep going. You need to finish what you started!"

I don't know if it was something in my voice, or something in our mutual need, but Kenzie's doubts vanished as quickly as they appeared. My sister kept riding me bareback, and her long black hair swept across my face and smelled like roses and sweat. I shifted my hands off her hips to reach up and play with her breasts as she kept pumping me, the movements a true statement of the degree to which we needed each other.

Deep within my body, I felt something start. This was a new sensation, but not completely new, I realized: I'd given myself one earlier this morning. "Oh Kenzie, Kenzie," I said, suddenly out of breath. "I'm going to cum."

"Me too, me too, me too," she said, her voice rising as she spoke.

Then I felt my ecstasy wash over me. I thought the orgasm I'd given myself that morning was powerful, but now my back arched so hard that it lifted Kenzie and me off her bed, and I felt like I turned into a bolt of lightning. The whole world stopped, except for Kenzie and me. We were the entire universe together.

Almost inaudible through the haze of glory, I heard my sister's soft, tiny whisper: "Please don't get pregnant."

Bit by bit, the rest of the world came back into focus. Kenzie and I had finished at the same time, and we collapsed on her bed, a tangle of limbs and sweat and hair. It took a moment, but I felt her starting to go soft inside me.

As our breathing slowed and our racing hearts returned to a more normal rhythm, Kenzie finally rolled off of me. We lay side by side, listening to each other's breaths. At last, she broke the silence with a soft murmur: "I've never felt anything that intense. Is it always like that for a boy?"

"Really?" I tried to sound surprised, but I didn't have enough wind in me to carry it off. "What, what I just felt, I thought it was more intense than what any guy ever felt. I thought girls must have it better."

She turned her head and gave me a languid smile. "Maybe it's not about the genitals," she whispered. "Maybe we just found the right partner for the first time."

I nodded. "I think maybe you're right."

But she didn't hear me. She had already drifted off to sleep, and I followed soon after.

* * * * *

When I woke up, the digital alarm clock on Kenzie's bedside table said it was two in the afternoon. We had slept for over four hours. At some point, she had rolled over slightly and draped her arm and leg across my body, and the warmth was so strong, I hesitated to do anything to disturb her.

But after a while, I definitely started to feel a crick in my back from laying still too long. I pushed her aside as gently as I could, and she rolled away, murmuring blissfully without words. And I sat up.

The minute I did so, I realized something about the weight of my body felt wrong. Something pulled down on my shoulders in a way I wasn't accustomed to. I looked down.

Sure enough, I had breasts.

My yelp of surprise was enough to awaken Kenzie. She propped herself on her elbows, and opened her mouth like she was about to ask a question. Then she followed my gaze and saw what I had seen.

After a moment, both of us stopped looking at my suddenly buxom chest and over at Kenzie. Yep, there she was, almost but not quite flat-chested. I had my sister's big beautiful rack, and she had my slight moobs.

The moment of awakening surprise drifted off us both, and Kenzie got a sudden wicked grin. She reached out to cup one of my boobs in her hand, and gently but firmly pushed me back so that I was lying down, with her looming over me.

"Oh, big brother," she said, moving her fingers around my nipple in exactly the same way I had done for her a few hours earlier. "I have big plans for these."