Suddenly his hands stiffened against my hips and he thrust me off his mouth, my twitching ass rising into the air.
"Sis! Jeez, sis!" His words were thick and slurred. "C'n I fuck you now? You gonna let me fuck you?"
I reluctantly pulled my head back to release the straining, leaping cock. "Yes." I swallowed convulsively, the heady flavor of his sweet cockhead lingering at the back of my throat. "Yes, hon, you can fuck me. You want to do that now?"
"Now, sis! Jeez, how much can a guy take?"
"Okay." I felt light-hearted and happy, now, my bitterness and self-pity washed away in the freshet of his innocent lust. "Okay, sweetie. Let go of my legs."
He let me get my knees under me again and I turned around to face him, straddling his waist and raising myself erect over him. He looked puzzled and rested his hands on the taut front muscles of my thighs, his thumbs burying themselves in my dark pussy-hair.
"Whatchya gonna do, sis?"
I didn't say anything. I simply reached under my gulping cunt and grabbed that lovely, rigid dick of his again and lifted it away from his belly. Raising it so it stood upright under me, I let myself down toward it, wiggling my hips so my pussy wove back and forth as they approached the now-trembling dome. My pussy-lips closed around the thick knob, their steaming wetness lubricating the contact and guiding the cockhead to the throbbing, greedy rim of my cunt-mouth.
Mark's eyes widened and a grin spread slowly across his lips. "Oh! Ohhh! I get it, sis! Oooeee…! This is going to feel like the greatest!"
We sort of flowed together. My cunt-mouth was hot and wet and stretchy from his sucking and his cockhead was so very smooth and round that the rubbery rim just gobbled the heavy knob right in. The hot, thick, soft walls of my vagina wedged apart as the inward-plowing cockhead bored its own passage between them and reamed the tube his shaft would lie in. As my cunt-rim slid down the length of the ribbed cylinder, I drew a deep, shaky breath and seized my own thighs.
"unnnhhh…! Mar-kee!" My words came out as jerky gasps. "How's… it… feeeeel!"
"Ynnnggg! Shit, sis…! W-w-warmmmm…! Aighhh…! Grrreat!"
The bristly, sparse wisps of his cock-hair jabbed into the gaping, inflamed membranes surrounding my sinking, cunt-mouth. My hot, oozing flesh molded itself over the bulging base of his cock and the front ridges of his thighs rose to meet my quivering, wriggling ass-cheeks.
Mark grabbed my wrists and squeezed, then lifted his hands to my swaying, full-sloped boobs and cradled them.
"Oh, fuck! Oh, fuck! The greatest, sis! A glove for my pecker! Just like a tight glove for it!"
I bounced a little bit and he gasped.
"Ohhh, shiiit!" he groaned. "Let me!"
He shifted his hands to my ass, raising me a couple of inches, and his hips snapped, jerking his ass off the lounge and plunging his stiff, deep-buried cock upward through the crowding organs. Dropping back, he thrust again and then again, each upward stroke ending when his hard cock-base slammed into my pussy. My tits leaped like water-filled balloons and my hair bounced all over my shoulders. I leaned forward enough to brace my hands on his belly and held my ass off him while he pounded at it with his pumping hips. His giant cockhead churned my belly and the thick, slippery dick-shaft scrubbed in and out through the tight-clamped rim of my cunt. I shuddered and shook my head giddily.
"Mmmmm…! Yaghhh…! Fuck me, sweetie…! Blast me!"
"Jeez, sis…! Oooofff…! Unnnhhh…! Right up ya!"
His blows speeded and strengthened. He hit my pussy hard enough to fling me right into the air, lifting my knees off the lounge, and I clung to him, my fingers biting into his sides to keep me from being thrown off.
"Oh, sweetie! Oh, sweeeeetie!" My voice shook, half sob and half laugh. "D-d-don't blast me loose!"
"Hang on! Oh, shit, hang on, sis!"
An enormous knot of excitement and tension was forming in the core of my belly: I knew I was going to blow into an orgasm within seconds and I wanted to be even closer to this dear, hot-blooded baby brother of mine. I dropped forward, my boobs squashing like pulp over his chest and my hair falling over my shoulders onto his. Tears wet my lashes and moans of happiness bubbled from my parted, twitching lips. I kicked back with my feet, extending my legs outside his, and let my pussy settle around the base of his cock.
"Oh, sweeetie!" I whispered. And I yelled. "Ooohhh, Honnneeey! Fuck haaarrrd…! Haaard…! I'm cummmiiinnnggg…! Cummmiiinnnggg!"
"Yeeeaggghhh…! Meee toooo…!Unnnhhh…! Nnnnn!"
"Make it, Markie…! Ohhh, mmmake-it!"
He stopped blasting and strained up under me, the base of his cock grinding my clitoris and the full, meaty cock throbbing inside me. The knot of excitement seemed to rupture, a great tide of hot pleasure surging over me and gut-twisting, spasmodic contractions squeezing my inner walls onto the implanted peter. I went rigid, arching my back and surrendering to the fierce tremor that took me in its grip. My pussy seemed to crawl on his hardness while he pulsed and jerked and his cum spurted against the upper end of my barrel. The warm jism pooled in me and my belly seethed with its new load. My ass-cheeks tightened and clamped together and I pushed my upper torso up with stiff arms to let my weight ride on his spewing cock.
"Aghhh… ummmmm… mmmmm…" I twisted violently and felt the inner convulsions easing. "Ohhh, honnneeey…! Sooo goood…! Markeee, baby!"
"Yummm! Sis, I never came that hard! Not ever!" He shivered and put his arms around me, crushing my naked, slender body against the sweaty, quivering, boy-flesh. "Hot, wet, tight cunt-walls, sis! They just milked everything I had out of me! Jeez, what a way to cum!"
In the returning awareness of my afterglow, I felt an abrupt need to make him understand. "Mark, honey…"
"Huh?"
"Marky, don't let fucking get to be just a wild, dirty way to get kicks. Always remember how good it can be when you feel right to start with."
"Huh! You blow your mind, sis?"
I tried desperately. "Listen, honey! Think! It's best when it means something besides just getting your balls off! When you're as close to a woman as you can get and you've still got to get closer, then fucking gets you closer!"
"Uh… okay… yeah, sis, I see what you're driving at. Okay."
I hoped he did. I lay in our sweat, sliding a little on his happily squirming belly, and made my cunt-mouth squeeze his softened prick affectionately. He giggled and bumped my pussy with his pelvic arch and raised his knees a little to force my thighs further apart.
And he sighed. "We sure fit together good, sis. You're nice to fuck."
By the note of contented love in his voice I knew he did understand. He might find the notion strange and foggy, but on a gut level he did understand.
"Marky… I love you…"
"Aww, sis…! Aw, I love you, too. But let's don't get all mushy. Okay?"
"Okay." I had to laugh. "Okay, sweetie."
"Hey, sis. This isn't going to be the only time, is it? We're going to fuck lots of times, aren't we? Please?"
"Sure. Sure, we will, Marky."
"And we won't always make it something real serious, will we?"
"No. We'll make it fun."