Mom caught me with my cock in my hand and the screen full of free mother son sex stories. She stood in the doorway of my room, her robe hanging open just enough to show the heavy sway of her tits. I was twenty-one, home from college for the summer, and she had walked in on me stroking to a story about a mom riding her son's dick.
"Jesus, Mark," she said, but her voice didn't sound mad. It sounded thick. "You into that shit?"
I didn't cover up. My hand stayed wrapped around my thick shaft, precum leaking over my fingers. "Yeah. You gonna tell Dad?"
She stepped inside and shut the door. The robe slipped off her shoulders and hit the floor. Her body was soft and full, wide hips, thick thighs, and a neatly trimmed patch of dark hair between her legs. Her nipples were already hard.
"Lock the door," she told me. "And pull up another one of those free mother son sex stories. Read it out loud while I suck that cock."
I did what she said. The story was about a mom catching her son jerking off and deciding to help. Mom dropped to her knees between my spread legs, grabbed the base of my dick, and swallowed the head in one hot, wet pull. Her mouth was tight and greedy. She bobbed fast, taking more each time until her nose pressed into my stomach and her throat squeezed around me.
"Fuck, Mom," I groaned, reading the next line. The words on the screen matched what she was doing.
She pulled off with a wet pop, spit dripping from her chin. "Keep reading, baby. Tell me how the mom in the story fucks her son."
I read while she climbed onto the bed and straddled me. She grabbed my cock, rubbed the fat head through her soaked pussy lips, and sank down hard. Her cunt was tight and burning hot, gripping every inch as she took me to the root. She started riding immediately, slamming her ass down, tits bouncing in my face.
"That's it," she panted. "Fill Mommy's pussy just like those stories say."
I grabbed her hips and thrust up to meet her. The wet sound of her cunt slapping down on my cock filled the room. She leaned forward, feeding a nipple into my mouth. I sucked hard while she ground her clit against me.
We switched positions fast. I flipped her onto her back, hooked her legs over my shoulders, and drove in deep. Mom's pussy clenched every time I bottomed out. She reached down and rubbed her clit in fast circles, eyes locked on mine.
"Harder," she ordered. "Fuck me like you mean it. Make me come on that big dick."
I pounded her. The bed slammed against the wall. Her tits shook with every thrust. She came first, pussy spasming and flooding around my cock, juices running down my balls. I kept fucking her through it until my own orgasm hit, blasting thick ropes of cum deep inside her.
We didn't stop there. She rolled me onto my back again and cleaned my cock with her mouth, tasting our mixed cum.

Then she climbed back on, this time facing away, and rode me reverse so I could watch her ass bounce. I slapped it red while she worked another load out of me.
By the time we were done, the laptop screen had gone dark, but we didn't need the free mother son sex stories anymore. We had our own.