If you want to know when I knew, it wasn’t going to be a normal afternoon? The second I heard Tessa say “I’m not kidding, Sienna, it’s freakish” and the sound of both sisters laughing out on the terrace. If you grew up with even one sister, you know that laugh: the kind where they’re absolutely talking shit, you’re the “shit,” and if you want plausible deniability it’s best not to ask.
I finished pouring the iced tea. Used her mom’s fancy glass pitcher, the one with lemon slices getting stuck in the spout. It was June, hot, and I still had my shirt stuck to my chest from the walk back. The house was all open windows, cheap rentals pretending to be Malibu, the air stinking of sunscreen and the ocean three blocks away.
I should say here, Tessa had been my girlfriend for maybe a month. She was the kind of girl who made everything look easy: sun-blonde, always tan, lip gloss on point even at breakfast. The kind of pretty where every other girl in the group chat got mean about it, but she’d never notice unless you said it out loud. She wore a yellow sundress. She also, and this is important, had zero filter when it came to my dick. This was the price of dating Tessa. If we were out with her friends, if she got even a single shot in her, she’d make a joke about how “he’s going to be trouble in college” or “I’ve had to ice my throat.” The first time it happened, I nearly died. After a while you stop getting embarrassed and just wait for the punchline.
Today the punchline was her little sister, Sienna, who was home for the week from UCSB, or maybe she’d dropped out, or maybe she was just between apartments, I could never tell with her. She was twenty-one, three years younger than me, but had that early-twenties attitude where she acted like it was already too late for the rest of us.
If Tessa was sun, Sienna was shade. Dark auburn hair, long, already slipping out of the clip onto her shoulders. Face all angles: long eyes, full mouth, almost no smile. Smaller waist than Tessa, heavier tits, a full D that the white tank couldn’t hold still. No bra, probably just to fuck with me. A thin chain sitting in her cleavage. Black shorts so little they crawled up her ass when she sat. She looked like she’d come back from ice cream dressed to start a problem.,
She was dangerous. Not in a “mean girl” way. In a “I will fuck your boyfriend just to see if you’ll notice” way.
I heard Tessa’s phone ring right as Tessa started telling Sienna about the time I split her, and she answered like it was nothing, like she hadn’t just outed me as some kind of novelty sex toy. “Oh my god, thank you,” she said, way too loud, “I’ll come back right now.”
She appeared in the kitchen, face pink from heat or gossip, probably both, and threw her arms around me. “Wallet. I left it at the counter. Can you survive here with her for like, ten minutes?”
“Try not to ruin my reputation while you’re gone,” I said.
Tessa squeezed my ass and left, keys jangling, and for two whole seconds the house was quiet. Then Sienna walked in.
She made a show of checking me out, up and down, like she was inspecting a rental car for damage. “Is it true?” she said.
I set the glasses on the tray and shrugged. “About the wallet? Yes. Tessa is the queen of losing stuff.”
She flopped onto the living room couch, which was barely ten feet from the kitchen. Her knees parted, careless. “Not that. Your whole…” She made a gesture with her hand like she was gripping a bat. “Your mythic junk.”
I felt myself flush. It was so fucking dumb, but if you’re a guy and a girl that hot asks you about your cock, you get dumb about it. “I don’t know. What’s the metric? Relative to what?”
She ignored that and poured herself ice tea, then took a long sip without breaking eye contact. “So is my sister a liar?”
I looked away and poured my own. “She’s just loud,” I said. “You know that.”
Sienna made a hmm sound, like she was unconvinced. “She said you made her cry the first time.”
“She’s dramatic,” I said, then regretted it.
“She said you broke her,” Sienna said. “She said it like she was bragging.”
I took a sip, cold sweet, and hoped my shorts weren’t betraying me. “She recovered.”
Sienna leaned forward on her elbows, tits resting on her knees. “I bet you could break me.”
I laughed because it was safer than letting her see my hands shake. “You want to try?”
“That’s the thing,” she said, “I kind of do.”
Sienna set her glass down and crossed her legs, and I realized she had nothing under those shorts but a black thong, visible when she shifted.
She nodded at the sliding door. “She’s probably halfway down the block.”
“She said ten minutes,” I offered.
“That’s a long time,” Sienna said, and then she stood, came around the couch, and looked up at me. “Do you wanna show me or are you scared I’ll tell her?”
“Tell her what?” I said, because I didn’t want her to think I was scared.
“That it’s not true,” Sienna said. She poked my chest, then hooked a finger in the collar of my shirt, and pulled so I bent toward her. “Or that it is.”
It was the kind of dare that only ended two ways. I could play it off, pretend I was too grown up to care, or I could let her find out.
I looked at her, then at the front door, then at her again.
Her mouth was right there, and her eyes said she was waiting for me to blink. I did.
She pushed me back with both hands, like she was shoving a locker closed, and I tripped over the side of the couch and landed on the carpet. She pounced, straddled me, hair falling around her face. It wasn’t graceful. It was like she’d been waiting to get her hands on me and didn’t care if it left marks.
She pinned my wrists, which was a joke because I could have bucked her off, but I didn’t. Her chest was right over my face, white tank gaping open. I could see her nipples, dark, heavy. She looked down at me and said, “If you want me to stop, just say so.” Then she bit her lip.
She weighed nothing but felt like a hundred pounds of intent. She held me down for one, two, three seconds, then let go and slid lower, her hips on my stomach. She pulled my shirt up, ran her palms up my abs, then popped the button on my shorts. It was fast, like she’d unzipped a hundred pairs before.
She laughed when she saw the way my cock already fought the fabric. “You’re not even kidding,” she said. “Jesus.”
I tried to keep it funny. “I mean, if you’re scared—”
She reached in and fished it out, no warning, just cold fingers, then hot mouth. Sienna didn’t even hesitate. She spat in her hand, stroked it, and then bent down and sucked the head, eyes up. Her hair tickled my stomach. Her tongue did shit I couldn’t describe except that I’d never had it happen that way before.
She took me deep, then deeper, then pulled off and wiped her mouth. “That’s what she meant,” Sienna said, and then she grinned, for real this time, and went right back to it, swallowing as much of my cock as she could.
I could have stopped her. Swear to god I could have. I thought about it, for like half a second, then I remembered the way Tessa bragged about it and how Sienna had listened like she wanted to be proven wrong. I didn’t want to disappoint her.
She stroked me with both hands, while sucking the swollen, purple tip, her tits swaying in my face. She let go off my cock, making it land with a smack against my waist. She climbed higher, up my chest, then held herself up with a palm on my shoulder and said, “Touch me.”
I did. She guided my fingers into her shorts. She was already really wet, and no thong to speak of now. I hooked my fingers in her and she dropped her head, hair in her mouth, eyes slitted shut. She started riding my hand, grinding down, and after a second she just pulled her shorts to one side and sat on my palm, letting me feel everything.
“Lemme undress.” She sat up, peeled the tank off, and those tits dropped free: pale, heavy, dark nipples tight, the chain still in the middle of them. She shoved the shorts and the thong down together, kicked them off, and then she was just bare on the carpet. Shaved except a dark strip, her pussy, pink as cotton candy and puffy to the point I wanted to devour her.
She let me finger her, then she pulled my wrist away and instead slid down until the head of my cock pressed against her. She looked at me, daring me to say no, but I didn’t.
She sank down and she was tight, too tight at first, but she took it, biting her own arm to keep from making noise. And the wetness sure helped. She settled her hips and shivered, then started to move. She was cock hungry, riding me like a pornstar. It wasn’t sweet at all. She slammed her hips down until she was full, then circled, then did it again. I could see the line of her body, her stomach so flat it hurt to look at, her tits swinging with every move.
She came first. She let it take her, loud and ugly, humping down on me and shaking, nails in my chest. I lasted maybe twenty more seconds. I tried to pull out, but she held me in and rode out the finish as I came hard deep inside her vagina, hips grinding, pussy gripping until there was nothing left.
She flopped forward, hair in my mouth, and let her tits crush against my chest while she caught her breath.
Outside, a car door slammed.
Sienna rolled off, landed on her back, and covered her face with both hands. Then she laughed, muffled. “I see why she’s obsessed,” she said.
I tucked myself away, hands still shaking. “This is fucked up, right?” I said.
Sienna propped herself on one elbow and looked at me, serious now. “No. Not if you’re gonna let me do it again later.”
We quickly got dressed, and Tessa came in, holding her wallet and a pint of extra ice cream. She didn’t notice anything, not the sweat, not the carpet burn on my shoulder, not the way Sienna and I avoided each other’s eyes. She just handed out the ice cream and told us about the cute cashier at the shop.
Later, after Sienna went to shower, Tessa curled up in my lap and whispered, “Did she ask you about it?”
“About what?” I said.
She smacked my thigh. “You know.”
I smiled. “She didn’t believe it, I think.”
Tessa beamed, smug. “Told you.”
I let her have the last word. Sienna came back with wet hair, same shorts, same look like nothing happened. She sat on the couch, crossed her legs, and winked at me.
I knew then it wasn’t a one-time thing. I also knew I’d let it happen again. If you want to judge, go ahead. That’s what sisters are for.
If it gets enough upvote, I might share a second part
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