My Toxic Stepbrother

Crossing the Line.

**Kai**

The cabin smelled like pine and old wood. My father and Elena left for their business trip two days ago. They thought sending us here alone would “help us bond.” They had no idea what they were doing.

I stood at the kitchen counter, watching Riley move around the small living room. She wore a thin tank top and shorts that rode up her thighs every time she bent to pick up a book. Three days of this. Three days of her pretending I didn’t exist while her eyes kept finding me.

She had avoided me since the last midnight visit in her room. Every time I got close, she walked away. But the cabin was small. Only two bedrooms, one bathroom, and nowhere to hide.

“Stop staring,” she said without looking up. Her voice was sharp.

I smirked and took a slow sip of my beer. “Can’t help it. You keep bending over like that.”

Riley straightened fast. Her cheeks turned pink. “You’re disgusting.”

“You like it.”

She didn’t answer. Instead, she grabbed her water bottle and headed for the back porch. I followed. The screen door slammed behind me. The night air was cool, but the heat between us stayed hot.

We had argued every day since we got here. Small things at first — who cooked, who left the dishes, who took the bigger bedroom. But tonight felt different. The tension had been building since the first night.

Riley leaned on the wooden railing, looking out at the dark trees. I stepped up behind her. Close enough that my chest almost touched her back.

“Move,” she said.

“No.”

She turned around fast. Her eyes flashed with anger. “What is your problem, Kai? We’re supposed to be here to get along, not… not whatever this is.”

I laughed once, low and rough. “Get along? That’s what they think? They threw us in a cabin together and hoped for the best. Stupid.”

Riley pushed at my chest. Her hands stayed there a second too long. “You started this. The touches, the kisses, the midnight visits. You won’t leave me alone.”

“Because you don’t want me to.” I grabbed her wrists gently but firm. I pulled her closer until her body pressed against mine. “Tell me right now you don’t feel it. Tell me you don’t think about my hands on you every night.”

Her breathing got faster. I could see her pulse jumping in her neck. “I hate you,” she whispered.

“Liar.” I leaned down. My lips brushed her ear. “You kissed me back in the living room. You let me touch you in your bed. You’re wet for me right now, aren’t you?”

Riley’s eyes widened. She tried to pull away, but I held her. Not hard enough to hurt, just enough to keep her there. “Shut up.”

“Make me.”

That was it. The match. Riley shoved me hard. I stumbled back one step, then caught her when she came at me again. Our bodies crashed together. Her mouth found mine in a rough kiss. It wasn’t soft. It was angry and hungry.

I groaned into her mouth and lifted her. Her legs wrapped around my waist like she had done it a hundred times. I carried her inside, kicking the screen door open. We knocked over a lamp. It crashed to the floor but neither of us cared.

I set her on the kitchen table. Her ass hit the wood with a thud. I pushed between her legs, my hands sliding up her thighs. Riley grabbed my shirt and yanked it over my head. Her nails scratched down my chest, tracing the tattoos she always stared at.

“Kai…” she breathed against my lips.

“Say it,” I demanded. I kissed her neck, sucking hard enough to leave a mark. “Say you want this.”

She moaned when my teeth grazed her skin. “I… f**k, I want it.”

I pulled her tank top off in one move. No bra. Her breasts spilled out, n*****s already hard. I took one in my mouth and sucked. Riley arched her back, her hands fisting in my hair. She made these little sounds that drove me crazy — half gasp, half whimper.

My hand moved down. I slipped it inside her shorts and under her panties. She was soaked. My fingers slid through her wetness easily. I rubbed her c**t in slow circles, then pushed one finger inside her.

Riley cried out. Her hips rocked against my hand. “Oh god…”

I added a second finger. I pumped them in and out while my thumb kept working her c**t. She was tight and hot around me. Her walls clenched every time I curled my fingers.

“Look at me,” I ordered.

She did. Her eyes were glassy, lips parted. Sweat already shone on her skin. I kissed her again, swallowing her moans while I f****d her with my fingers.

The table creaked under us. I could feel how close she was. Her breathing turned ragged. Her thighs shook around my hips.

Then I pulled my hand away.

Riley made a frustrated sound. “Kai, don’t stop—”

“Not yet.” I picked her up again and carried her to the bigger bedroom. I dropped her on the bed. She bounced once, then watched me push my sweatpants down. My c**k sprang free, hard and aching.

Riley’s eyes widened. She licked her lips without thinking. That small move almost made me lose control.

I crawled over her. I kissed her deep and slow this time. My hands explored every inch — her breasts, her waist, the curve of her hips. I pulled her shorts and panties off together. Now she was completely naked under me.

I settled between her legs. My c**k rested against her wet p***y. I rocked my hips, sliding along her folds without pushing inside. The friction felt insane.

Riley whimpered. Her hands gripped my shoulders. “Please…”

“Please what?” I whispered against her mouth. I kept grinding slowly, teasing her c**t with the head of my c**k. “Tell me you need me.”

“I need you,” she gasped. Her nails dug into my back. “Kai, I need you inside me.”

I almost gave in. I lined myself up, the tip pressing against her entrance. She was so wet I could feel her heat pulling me in. One thrust and I would be buried inside her. One thrust and there would be no going back.

But I stopped.

I pulled back just enough. Riley’s eyes flew open in shock and frustration.

“What are you doing?” she demanded. Her voice cracked.

I smirked down at her. My chest heaved. Sweat dripped from my forehead. “I want you desperate. I want you begging for it every night from now on.”

“Kai, you asshole—”

I cut her off with a hard kiss. I rolled us so she was on top. Her body pressed against mine, slick and trembling. I gripped her ass and rocked her against my c**k again, letting her feel how close we were without finishing it.

We made out heavy for long minutes. Hands everywhere. Her grinding on me, my fingers digging into her skin. I sucked marks onto her neck and breasts. She bit my shoulder hard enough to leave teeth marks.

The pleasure built sharp and intense. I could feel her getting close again from the friction. I held her hips and moved her faster.

“Come like this,” I growled.

Riley shook. Her moans got louder. She buried her face in my neck as she came, her body jerking against mine. I held her through it, my own release so close I had to bite my lip to stop from finishing right there.

When she finally went still, breathing hard, I kissed her forehead almost gently.

I rolled her off me and pulled the sheet over her naked body. She looked wrecked — lips swollen, skin flushed, eyes heavy.

“You’re going to be mine, Riley,” I said quietly. My voice was rough. “Whether you like it or not.”

She didn’t answer. She just stared at me, body still trembling, realizing she had fallen deeper into my twisted game.

I got up, pulled my sweatpants back on, and left the room before I changed my mind and took everything.

The door clicked shut behind me.