The city fell almost overnight. Patient zero pounded his infected seed into his night-shift nurse just after shift change. She went and spread her infected juices over her the cocks of her male coworkers and a dozen or so other patients. Some of those patients magically healed, and began heading home to make love to their wives, stopping to pound any drunk college girls they saw on their unknowingly final bar crawl. They spread it to the frat bros, at which the infected population booms exponentially. 

Going back to the hospital, some of the fucked patients were too injured to magically heal. Instead, their bodies mutated, grew additional limbs or tentacles, turning them into grotesque resident evil-esque monsters. 

Everyone calls it the sex virus not because it spreads through sex; it does so by infecting the brain first, activating the right neurons and hormone transmitters to make the infected constantly horny. Then, it increases fluid production, of which the most effective is semen, or for women, their natural lubricant. Cock size increases dramatically in men, as does breast size in women, and lactation begins even for women who could not previously. 

Sweat production increased as well, and, as the body heated up in an attempt to burn out the infection, the infected sweat evaporated, sending particles of the infection into the air, coalescing into a thick pink mist. After a week, this pink mist rested in a foot-thick layer on the ground. When inhaled, it didn’t infect you immediately, but it activated the horny neurons in your brain as if you were. It made it hard to resist the infected who already wanted to fuck you. But the question remained: what did it feel like to be one of them?

[M4F] A “Sex Virus” has surfaced in a big city, causing the place to turn into a monstrous breeding ground (tentacles, apocalypse, bad ends, and monsters)