I stopped again after another inch. Fuck, her asshole was tighter than Michelle’s pussy. “Maybe we should stop.”
“Don’t you fucking dare!” Alex howled before letting her arms collapse so that her face mashed into her folded arms beneath her while her ass was still up in the air, half-skewered by my cock.
Michelle’s voice suddenly sounded behind me. “That sounds REALLY painful.”
I glanced back to see my little sister standing in the doorway, arms folded across her chest. Even the frown on her face couldn’t detract from her beauty. In particular, her long, fine hair shimmered in the light filtering through Alex’s gauzy window shades, and my heart was filled with love at the mere sight of her.
But Michelle’s expression and stance were anything but sexy at the moment, and the clenching of Alex’s abused anal muscles brought me back to the task at hand (err, ass).
Alex muttered, “You missed seeing the entry part.”
Michelle replied, “I saw the entry part when -I- did it to you.”
“Not like this you didn’t. His dick is bigger than my strap-on.”
“Which is why he’s NEVER putting that baseball bat in my ass.” Michelle shook her head emphatically.
“Don’t knock it ‘til you try it,” Alex wheezed, a silly grin on her face. “Fuck you’re thick, squirt. You’re gonna ruin me.”
I sighed. “Half the words coming out of your mouth say you absolutely love this. The other half say I’m causing you extreme agony. Which is it?”
“Yesss...” she hissed.
I sighed and held my current position, letting her get used to it with clenched teeth until she finally exhaled and said, “Okay. Gimme the rest.”
“You sure?”
“Fuck my ass, little brother.”
“But—”
“Yes, my butt. Fuck it!”
“Lex—”
“FUCK MY FUCKING ASS, YOU FUCKING ASSHOLE!” Alex howled, her tone one of command. I was so used to reacting to my big sister’s “big sister” voice that I rammed my hips forward without thinking about it, slamming in the last three inches all at once.
“FUUUUUUCCCKKKK!!!” Alex howled.
“I’m sorry!”
“FUUUUUUCCCKKKK!!!” she howled again.
“You told me to—”
“FUUUUUUCCCKKKK!!!”
Alex was cumming. It was pretty obvious. Her ass muscles spasmed rhythmically, the same way her pussy muscles did whenever she orgasmed. Her whole body shuddered and shook in the same manner. And of course, there was the whole screaming bloody murder part.
And then all of a sudden, her anal chute relaxed.
Huh. Mental note: Make her cum and relax before trying to shove my dick inside.
Alex’s knees collapsed just then as well, and she fell flat face-down across her bed. I got yanked down along with her, because even when “relaxed” her butthole still gripped my dick like a third hand, and I wound up sprawled across her body.
“Fucking A...” Alex sighed rapturously, drooling just a little bit with her face turned to the side. Her arms were splayed out to the sides and angled back towards me, like airplane wings, with her palms up. And her legs were together, a position that really squeezed her ass tight around the 8 inches of brother-dick lodged in her rectum.
“You okay?” I asked, genuinely concerned.
“Biggest orgasm you’ve given me yet. I’m so sensitive,” my sister groaned. “We should’ve done this a long time ago.”
I took a deep breath, her words finally convincing me that she actually wanted this. “Well, I’m glad you’re enjoying it now,” I said truthfully.
“More, though. You’re not moving. Fuck my ass, squirt. Fuck my ass...”
Propping myself up on my elbows, I dug my toes into the mattress and raised my hips, withdrawing several inches before relaxing and pushing down once again. And then up. And then down. At this angle, it felt like I was vertically drilling into her core, working my ab muscles like I was doing planks.
“So tight,” I groaned as the pleasure built. It had never NOT felt good to be inside Alex’s asshole, but I was too worried about whatever pain she felt to really enjoy myself. It really was tighter than Michelle’s virgin pussy, extremely hot, and not as moist despite the copious amount of lube we’d used. That all added up to an incredible amount of friction on my cock, which felt amazingly good and yet a little painful at the same time.
“Fuck my ass...” Alex hissed as I started to speed up a little. “Gawd-fucking-dammit, I’m gonna cum again already. Fuck my ass ... Make me cum on your fucking cock in my tiny asshole, big brother. Fuckme, fuckme, fuckme.”
I was fucking her. I started fucking her a little harder. And I started fucking her a little faster. But my abs were doing all the work, and even my six-pack couldn’t keep this up forever. I pulled all the way out, causing Alex to whine that she felt so empty. But I quickly dragged her to the edge of the bed and stepped onto the floor. By tucking her knees beneath her, I was able to put her gaping-open sphincter at the right height. And after pressing my mushroom head back into her backdoor, I grabbed her hips and swiftly filled her with eight inches of brother dick once more.
“Oh, FUCK! I think I came again when you rammed into me,” my big sister grunted. “Do it again!”
With a chuckle, I pulled all way out again, marveling at the sight of her black hole. I quickly eclipsed that hole with my dickhead, lined myself up, and slammed it all in.
“Fuck-FUCK!” Alex yelled and then started laughing.
“Shit,” Michelle commented as she came to sit beside us on the bed, staring intently at the point where brother-cock penetrated sister-anus. “She’s really into this!”
“You’d better fucking believe it,” Alex growled through gritted teeth. “Hurts so bad but feels so good. I wouldn’t be able to do this every day, but as an occasional treat ... Fuck, bro, I think I might need this once a week.”
I chuckled and quipped, “Lemme check the calendar. Oh, wait, we’re locked down in the middle of a pandemic.”
“Fuck, fuck, fuck,” Alex continued to chant as I started pounding her faster and faster. Now that I had my legs under me, I could really lay down the lumber. Every now and again, I would pull all the way out, just for her to enjoy the feeling of going from empty to full in half a second, and for me to enjoy the sight of her gaping anus welcoming me back in.
But all that pounding was wearing me out. My legs were fine - we actually hadn’t been fucking that long, and I’d had sex for far longer than this without cumming before. But my ejaculatory control was rapidly slipping away. Her asshole was just too hot and too tight and too GOOD. I could feel my neck muscles straining, of all things, as I fought to keep my orgasm at bay. But eventually I knew I was gonna lose it, and I growled, “Gonna cum, Lex. Gonna fill your fucking asshole with my sperm.”
“Do it, BIG FUCKING brother. I wanna feel my fucking colon drowning in brother jizz that I’ll be shitting out of me for DAYS. Fuck my ass and fill it! Fucking fill me and— FUUUUUUCCCKKKK!!!“
She screamed as I slammed forward one final time and unleashed hell. A volcano erupted deep inside of me, blasting hot lava into the unholy fathoms of Alex’s anal depths. Over and over I spewed scalding hot spunk into my big sister’s bowels. And I yelled right along with her, howling my release until my voice gave out even while my cock kept cumming.
At last, we were both spent. My muscles gave out and I collapsed forward, catching myself on my hands lest I drop onto my sister’s naked back. It took me thirty seconds to catch my breath enough to extract my dick from Alex’s lewdly stretched anus. And I quickly spun around to sit heavily on the edge of the bed, gasping for air as I glanced down to make sure my big sister was okay.