Attack on a commuter train

Brian hated being crammed into the train during rush hour. He stood pressed up against the other passengers, his body jostling with each stop and start. He was stuck with a large man muscular man pressed against him, chest to chest. Brian tried to lean back, but there was nowhere to go. The man's bulk pinned him in place, and the warmth of the other man's body sent a shiver through him. Why was he getting worked up? He's heard of claustrophobia but not people getting aroused by being trapped.

His dick grew harder still, and he couldn't help but grind against the bulge in the other man's pants. The man let out a low chuckle and wrapped an arm around Brian's waist, pulling him tight against his groin. Brian's moaned at the increased contact. He couldn't believe he was doing this. This sort of thing only happened in those stories about Martian...FUCK! Huge, muscular dude making people uncontrollably horny. This guy was a Martian and he was squeezed right up against him!

Frozen in shock, Brian didn't react when the Martian pulled down Brian's pants, revealing his growing hard-on. With a swift motion, the Martian grabbed his own cock and positioned it at the base of Brian's cock. Instead of thrusting forward, he paused. The Martian knew. The Martian knew Brian had caught on and was taunting him by holding back right before he got bitched. Brian wanted to be pissed at this alpha bastard lording over him, but he was soooo horny. Brian was pissed, but it was because the Martian still wasn't fucking him. Brian thrust his hips forward, forcing the Martian's cock to press into him slightly, starting the formation of his new pussy. It was unlike anything he had ever experienced before; the sensation of something inside him scratched an itch he hadn't realized existed.

"Please," Brian begged, "Don't drag this out. Fuck me. Fill me. Make me your bitch. Turn all of us into your sluts."

"Oh this is too precious," the Martian said, "here I thought this would be an easy way to pick up a whole brood, but I never met a slut like you. Usually human men try to put up a masculine front, but you knew just what you were. There's always been a slut inside you, but unlike these others who try to bury it deep yours was right there under the surface. Don't worry honey, you'll make an excellent breeder."

Brian gasped as the Martian began to thrust into him, each motion sending waves of pleasure through his body. The train ride that had seemed so unbearable only moments ago now felt like paradise. As the Martian fucked him harder and faster, Brian couldn't help but moan in ecstasy. He was no longer concerned about what everyone else on the train was thinking; all he cared about was the delightful sensation of having his new cunt pounded. With each thrust, he felt himself being transformed, becoming more delicate and feminine. His hands went to his chest as a jiggling announced the formation of his new breasts.

The crowded train finally realized something was wrong.