I thought sleep might finally hit after the second creampie.
Wrong.
Barely an hour later the ladder creaked again. Mia's face appeared at the edge of my bunk, eyes gleaming like a cat that just found cream. Her tank top was back on, crooked, one full tit almost spilling out. Fresh streaks of my cum already dripped down her inner thighs.
"I can't sleep," she whispered, thick with hunger. "Every time I move I feel you leaking out… and it just makes me want more. Get hard again, little bro. Right now."
She didn't wait. Climbed up, shoved my shorts down, and swallowed my half-soft cock in one warm, sloppy suck. One slow swirl of her tongue and I was rock-hard, throbbing against the back of her throat.
"Third load tonight," she murmured around my shaft, popping off with a wet string of spit. "Then a fourth. I want you overflowing me."
She swung her leg over and sank down face-to-face, tits crushed to my chest, mouth hovering over mine. Her pussy was so sloppy from the earlier loads I slid balls-deep with zero resistance. The loud schlick made us both freeze, listening for footsteps downstairs.
Nothing.
Mia grinned like pure sin and started riding—deep, grinding rolls that dragged her clit along my base every time she bottomed out. The bunk frame groaned louder with every thrust. She grabbed the headboard with both hands and slammed down harder, tits bouncing in my face.
"Fuck… I keep thinking about Mom's panties in your drawer," she panted, voice low and filthy. "All those loads you wasted on her lace when you could've been pumping them straight into me… or into her."
She reached over, yanked the drawer open again, and pulled out two clean pairs she'd clearly stolen earlier—one tiny red lace thong, one silky black bikini.
"Watch this," she breathed.
She pressed the red thong against her clit while she rode, rubbing the soft lace in tight, nasty circles. The black pair she draped over my face like a mask, crotch right on my nose. Sophia's warm, sweet pussy scent flooded my lungs.
"Smell her while you fuck me," she ordered, bouncing faster. "Imagine it's Mommy's tight cunt squeezing your cock instead of mine."
I groaned into the fabric. My hands spread her ass cheeks so I could feel every inch. The bunk was creaking dangerously now, metal joints screaming, but we didn't slow.
"I'm gonna cum again," I warned, voice wrecked.
"Do it," she hissed. "Fill me. Breed your stepsister while you sniff Mom's panties."
Her walls fluttered. Milked.
I exploded—third thick load—pumping rope after rope so deep I felt it splash back. Mia bit my shoulder to choke her moan, thighs shaking as she came with me, grinding like she was forcing every drop into her womb.
But she didn't stop.
She kept riding through the aftershocks, sloppy and loud, three loads now frothing white around my shaft and dripping onto the sheets.
"Fourth one," she demanded, eyes wild. "Right fucking now."
She spun around—reverse cowgirl again—planted her feet and bounced like a pornstar. The entire bunk bed shook. Her ass clapped loud against me. She balled the black bikini panties and ground them against her clit while she rode.
"Gonna stuff these with your cum tonight," she panted. "Then tomorrow we sneak them into Mom's hamper… still warm and dripping. Let her find her own panties full of her stepson's load."
The words hit like a trigger. I grabbed her hips and thrust up hard, burying myself to the root as the fourth load erupted—heavier, thicker, endless. Mia slammed down one last time and came so hard her legs gave out. She collapsed forward, still impaled, pussy spasming around me as the last spurts filled her to bursting.
When she finally slid off, a river of cum poured out—four loads mixed together, thick and white, soaking the sheets and running down her thighs in messy trails. She scooped some up, licked it clean, then used the red thong to wipe the rest from her dripping pussy.
She held up both pairs—now warm, sticky, and thoroughly ruined.
"Gifts for Mommy," she whispered with a wicked grin. "Tomorrow morning we sneak these into her hamper… and wait for her to notice."
She climbed down the ladder, panties clutched in her hand, and curled up on the bottom bunk like the innocent little stepsister she definitely wasn't.
I lay there panting, cock still twitching, sheets absolutely destroyed.
Four loads in one night. Sophia's panties about to get a fresh, warm surprise. Four months of sharing this room still ahead.
We were playing with fire.
And I couldn't fucking wait for it to burn us alive.
End of ch 5.