The studio lights burned hot on the animation cels, but nothing compared to the heat between us. I slammed the door to the private screening room and shoved my sister against the wall, my hands already yanking up her tight cartoonish skirt that hugged her ass like it was drawn for sin. "You fucking tease," I growled, fingers digging into her soft thighs. "Parading around in that voice-over booth like you don't know what it does to me."
Mia laughed, low and filthy, her cartoon-red lips parting. "Like you weren't stroking that big cock under the table every time I moaned my lines, big brother? 'Oh yes, fuck me harder' – sound familiar?" She reached down and grabbed my dick through my jeans, squeezing hard. "Cartoon or not, this shit is real now."
I spun her around, bent her over the leather couch, and ripped her panties aside. Her pussy was already dripping, slick and pink, just like the exaggerated drawings we voiced for those underground adult toons. I spit on my fingers and shoved two inside her, pumping fast. "Goddamn, you're soaked. Been thinking about my cock all day while we recorded that brother-sister scene?"
"Fuck yes," she hissed, pushing back on my hand. "Every time you growled those dirty lines into the mic I wanted to climb over the console and sit on your face. Do it. Eat this cartoon cunt."
I dropped to my knees, spread her cheeks, and buried my tongue in her. She tasted sweet and dirty at the same time, like forbidden fruit rendered in ink and lust. I licked from her clit up to her tight asshole, circling and sucking while she moaned loud enough for the whole empty studio to hear. "That's it, lick your sister's holes. We're so fucked up and I love it."
My cock was throbbing, leaking in my pants. I stood, unzipped, and slapped my thick shaft against her ass. "You want this in you? Say it."
"Shove that dick in your little sister's cartoon pussy right now," she demanded. I lined up and drove in balls-deep in one thrust. She screamed, clenching around me like a vice. I fucked her hard, the wet slap of skin echoing off the walls, her cartoon-perfect tits bouncing as I pounded her from behind.
"Take it," I grunted, gripping her hips. "This is what happens when we spend all day pretending to fuck for the cameras. Real thing's better, isn't it?"
"Harder, you bastard," she begged. "Make me come on my brother's cock."
I reached around and rubbed her swollen clit in fast circles while I hammered into her. She came with a shout, pussy pulsing and flooding my shaft. I didn't stop. I pulled out, flipped her onto her back, and shoved back in, watching her face twist in pleasure. Her legs wrapped around me, ankles locked.
"Fill me up," she panted. "Paint your sister's insides. We've been drawing this scene in our heads for years."
I slammed deep one last time and exploded, pumping thick ropes of cum into her. She milked every drop, grinding against me until I was empty and shaking. We stayed locked together, breathing hard, the smell of sex thick in the air.
Mia grinned up at me, lazy and satisfied. "Round two in the sound booth? I want to record our real moans over the cartoon ones."
I was already getting hard again inside her. "Fuck yes. Let's make our own incest sex cartoon stories."
