Girlfriend Betrays Boyfriend with His Bigger-Cocked Friend

The apartment was too warm for early October, the windows cracked and the ceiling fan ticking, and Corinne had already kicked her heels under the couch by the time Sullivan dropped onto the cushion beside her. Callum, twenty-six and still in the button-down from his office, queued the movie and passed around the last of the takeout. He had been dating Corinne for fourteen months. Sullivan, his best friend since college, was twenty-seven, built like someone who actually used the gym membership Callum kept forgetting, and he treated their place like a second living room. Most Friday nights he was there. Most Friday nights Corinne managed not to stare.

Tonight the shorts were the problem.

Sullivan shifted, one knee drawn up, and the thin gray cotton pulled tight across his lap. Corinne’s gaze snagged and stayed. The outline was unmistakable and enormous—thick where it rested against his thigh, long enough that the head pressed a clear ridge near the hem, heavy even soft. Her mouth went dry. Heat crawled up her neck and settled low in her stomach, a sudden, stupid throb between her legs that had nothing to do with the movie Callum had just started. She crossed her ankles and tried to look at the screen. Failed. Looked again. The shape of him moved when he laughed at something Callum said, and she felt herself get wet against the cotton of her panties, a slick little betrayal she hoped no one could smell.

“You good?” Callum asked, not turning around from the remote.

“Fine,” she said, too fast. She dragged her eyes up to Sullivan’s face and found him already watching her, one brow lifted, the corner of his mouth almost amused. He didn’t adjust the shorts. He let her look. She looked until her pulse was loud in her ears, then fixed her stare on the television and kept it there with an effort that made her thighs ache. Callum never noticed. He laughed at the opening scene and slid an arm around her shoulders, and she leaned into him while her skin stayed hot from the man sitting two feet away, the massive shape of his cock still printed behind her eyes.

The next week the air between them turned electric every time Callum left a room.

Sullivan came by after work on Tuesday, ostensibly to return a charger. Callum stepped into the kitchen for beers. The second the fridge door thumped, Sullivan’s voice dropped. “You’ve been staring at my dick since Friday.”

Corinne’s face burned. “It was right there.”

“And you liked what you saw.”

She should have told him to shut up. Instead she heard herself say, “It’s bigger than his. A lot bigger.” The words tasted reckless and true. Sullivan’s eyes darkened. Callum came back with bottles and the moment folded itself away, but her phone buzzed twenty minutes later, Sullivan’s name on the lock screen.

Still thinking about it?

Yes. Don’t text me while he’s here.

Then tell me when he isn’t.

They kept going like that for days—short, filthy lines traded in the gaps. She told him she had touched herself in the shower imagining how thick he would feel. He told her he had gotten hard in his car outside their building thinking about her mouth. She read that one in the bathroom with her hand over her lips, pussy clenching around nothing, and typed back that she wanted to find out if she could even take him. He answered: You will. I’ll make you.

Thursday night Callum announced he was getting in the shower before they ordered food. Sullivan was on the couch again, long legs spread, watching her over the rim of a glass of water. The bathroom door closed. The water started. Corinne stood in the hallway with her heart hammering and her panties already damp, and Sullivan rose without being asked.

“Bedroom,” she said, voice thin. “Now. Before I lose my nerve.”

He followed her in and shut the door most of the way, leaving a crack so they would hear the shower cut off. The room smelled like her perfume and Callum’s laundry. She faced Sullivan in the low lamp light, twenty-five years old and shaking with want she had been feeding all week, and said it plain. “I want you to fuck me. Behind his back. I’ve wanted it since I saw you in those shorts.”

“Say it again.”

“I want your cock. The big one. I want you to fuck me while he’s in the shower and not know.” Her hands were already at his waistband. “Please.”

“Good,” Sullivan said, and the word went through her like a hand. “Because I’ve been hard for you all week, and I’m not stopping once I start.”

She dropped to her knees on the rug before he finished the sentence.

His cock sprang free heavy and hot, and the reality of it stole her breath. Thicker than Callum by a wide margin, longer, the head broad and flushed, veins standing along the shaft, the weight of it filling her palm and then some. She had to use both hands to stroke him. Precum beaded at the slit and she licked it off, salty, moaning at the taste and at the sheer size. She opened her mouth and took the head, jaw stretching immediately, lips sealed tight around a girth that made her eyes water. She worked down an inch, then another, drool spilling over her chin because she couldn’t close her mouth properly around him. She gagged, pulled back, strings of spit connecting her lips to his cock, and went down again with a desperate little sound.

“Fuck,” Sullivan breathed, one hand in her hair, not forcing, just holding. “Look at you struggle.”

She pulled off, gasping, chin wet. “He’s never this thick. I can take Callum easy. You—” She licked a long stripe up the underside, eyes half-closed. “You feel so much better already. I can barely get my mouth on you.” She sucked him again, sloppy and eager, moaning around the head, one hand pumping what she couldn’t swallow, the other braced on his thigh. Her pussy ached, empty and soaked, panties ruined. She wanted him deeper than her throat could manage. She wanted him everywhere.

Sullivan lasted until her mascara smudged and her jaw trembled, then he hauled her up by the arms and turned her toward the bed. “Bend over.”

She did, palms on the mattress, ass up, the hem of her dress shoved to her waist. He yanked her panties aside instead of off. Two fingers slid through her folds and came away glistening. “Dripping,” he said, almost wondering, and then the broad head of his cock pressed at her entrance and pushed.

The stretch stole a cry out of her. He was slow for the first inch and relentless after that, sinking into her inch by thick inch while she clutched the comforter and tried to breathe. Fuller than she had ever been. Deeper. When his hips finally met her ass she was shaking, stuffed so completely her toes curled in the rug. He drew back and drove in again, a deep, powerful stroke that knocked a broken moan out of her chest. Then another. Then a rhythm, hard and steady, the wet sound of her pussy taking him loud in the small room.

“Oh god—Sullivan—fuck, you’re so deep—”

“Tighter than I thought you’d be,” he said, gripping her hips, pounding her from behind until the bed frame tapped the wall in a careful, muffled beat. “Taking every inch. Good girl.”

She pushed back to meet him, greedy, the slap of his hips against her ass turning her thoughts to static. Every stroke dragged over places Callum’s cock had never reached. She was going to come just from being filled. She told him so, voice wrecked, and he laughed once, low, and kept fucking her until her legs threatened to give.

He pulled out. She whimpered at the sudden emptiness. He sat on the edge of the bed, cock shining with her, and hauled her into his lap facing away—reverse, her back to his chest, her feet barely finding the floor. She reached down, lined him up, and sank onto him with a long, helpless groan. Gravity did the rest. He bottomed out and she saw stars.

“Ride it,” he said.

She did. Up and down, slow at first so she could feel every thick inch drag out and punch back in, then faster, chasing the friction, her ass bouncing against his thighs. His hands came around and slapped her, sharp and open-palmed, once on each cheek, the sting blooming hot under her skin. She cried out and clenched around him and he slapped her again, harder, while she rode.

“His cock is nothing,” she panted, the words tumbling out filthy and true. “You’re ruining me for him. I can feel you in my stomach. I’m never going to feel him after this—fuck—your huge cock is ruining me, Sullivan, don’t stop, don’t you dare stop—”

He slapped her ass again, both hands gripping the reddened skin, and thrust up to meet her. The angle hit something devastating. She came with a choked sob, pussy pulsing around his girth, thighs shaking, dress stuck to her sweat-damp back. He didn’t let her collapse. He lifted her off, turned her, and laid her on her back across the bed, pushing her knees up and open.

Missionary. His weight over her. His cock sliding back in to the hilt in one smooth, brutal stroke that made her eyes roll. He fucked her like that, deep and intense, forearms braced beside her head, their breath mixing, her nails in his shoulders. She locked her ankles behind him and took every thrust, moaning into his mouth when he kissed her, tasting herself on his tongue from earlier, from her own spit. The shower still ran. She didn’t care. She only cared about the thick drag of him, the way her pussy clung and fluttered, the way he groaned when she squeezed.

“Inside,” she begged. “Cum in me. Fill me up. I want it.”

He drove in hard, once, twice, and came with a rough sound against her throat, cock jerking, pumping thick heat deep into her. She felt every pulse. She held him there, legs tight, milking him, a second smaller orgasm shivering through her while he emptied himself. They stayed locked together, panting, the room loud with their breathing and the distant hiss of water.

Sullivan pulled out slowly. They both watched. His load welled at her entrance and spilled, a thick white trickle sliding down over her ass and onto the comforter, more of it following when she clenched. She was flushed, hair a mess, mouth swollen, looking wrecked and deeply satisfied. She touched the mess with two fingers, brought them up, and smiled at him, breathless.

“I’m going to keep fucking you,” she said. “Every chance we get. Whenever he’s in the shower, whenever he’s late, whenever you can get me alone. I want this cock again. I want you to keep filling me until I can’t walk straight back to him.”

“Yeah,” Sullivan said, voice rough, watching another drip slide free. “Whenever you want it.”

They moved fast after that. She cleaned herself with tissues from the nightstand, pulled her panties back into place over the lingering slick, smoothed her dress, fixed her hair in the mirror with shaking hands. He tucked himself away, the outline still obscene even soft, and they listened. The shower cut off. A minute. The bathroom door.

They were on the couch when Callum came out in sweatpants, towel over his shoulder, asking if anyone had picked a restaurant yet. Corinne’s voice came out even. Sullivan answered something ordinary about Thai. Callum sat between them and reached for the remote, oblivious, warm from the shower, talking about a meeting tomorrow. Behind his back, where he couldn’t see, Corinne turned her head just enough to meet Sullivan’s eyes. Her pussy still throbbed, full of him, panties damp again already. She let the corner of her mouth lift. He answered with the same small, wicked curve, private and sure, and then both of them looked at the television as if nothing in the apartment had changed at all.

The fan kept ticking. No one spoke. The quiet held.