Mike had both girls naked on the bed within minutes of locking the bedroom door. Lisa, his girlfriend, was already wet and spreading her legs, while Sarah, her best friend, knelt beside her with that hungry look in her eyes. They had talked about this threesome for weeks, but nobody said anything about who was getting what. Mike just wanted to fuck.
He started with Lisa, shoving his cock into her pussy while Sarah watched and fingered herself. Lisa moaned loud, telling him to pound her harder. Sarah leaned in and started sucking on Lisa's tits, then reached down to rub Lisa's clit while Mike fucked her. The room smelled like sex already.
After a few minutes Mike pulled out and told Sarah to get on all fours. She did it fast, ass up, and he slammed into her from behind. Sarah was tighter than Lisa, and she pushed back against every thrust, grunting dirty shit like "fuck me deep" and "use that pussy." Lisa crawled underneath Sarah and started licking Mike's balls while he fucked her friend. The feeling of two mouths and one tight cunt had him close already.
He switched back to Lisa, flipping her onto her back and driving into her hard. Sarah straddled Lisa's face so Lisa could eat her out while Mike fucked his girlfriend. The sounds were filthy, wet slaps and moans and Sarah grinding on Lisa's tongue.

Mike watched his cock disappear into Lisa, thinking he should probably pull out soon because nobody had brought up condoms or pulling out.
Sarah got impatient. She climbed off Lisa's face and shoved Mike onto his back, then sank down on his cock herself. "My turn," she said, riding him fast and rough. Her tits bounced and she kept talking, telling him how good his dick felt. Lisa moved up and sat on Mike's face so he could lick her while Sarah fucked him. Everything was slick and hot and nobody was thinking straight.
Sarah leaned forward, changing the angle, and started grinding her clit against him. Mike felt his balls tighten. He was right on the edge. Sarah kept bouncing, pussy clenching around him, and Lisa was moaning on his tongue. In the rush of it, Mike grabbed Sarah's hips and thrust up hard, unloading deep inside her without even realizing what he was doing until it was happening.
Sarah froze for a second, then pushed down harder, taking every spurt. "Oh fuck, he's cumming in me," she gasped. Lisa lifted off Mike's face just in time to see his cock pulsing inside her friend, cum already leaking out around the base. Mike's brain caught up too late. He had meant to pull out and finish on Lisa, but he had just pumped Sarah full.
Nobody stopped. Sarah kept riding him slowly, milking the rest out, while Lisa watched with wide eyes and then started rubbing her own clit. "You came inside her," Lisa said, voice low and turned on instead of pissed. Sarah slid off Mike's still-hard cock and a thick load dripped out of her onto his stomach. Lisa leaned down and licked some of it up, then pushed Sarah onto her back and dove between her legs, eating the cum out of her friend while Sarah moaned.
Mike watched them, cock twitching again already. He moved behind Lisa and slid back into her pussy, fucking her while she licked Sarah clean. The three of them kept going, switching positions, nobody mentioning the mistake because it clearly wasn't one anymore. Sarah came hard on Lisa's tongue, and Mike pulled out of Lisa at the last second this time, shooting across both girls' tits and mouths.
They collapsed in a sweaty pile, breathing hard. Sarah reached down and scooped some of Mike's cum from her pussy, licking it off her fingers with a grin. Lisa just laughed and kissed her, tasting it. Mike lay there catching his breath, realizing the night was far from over and nobody was mad about where he had finished. They were already touching each other again, ready for round two.