Jack grabbed the condom with the horse on the packaging. He had always liked horses. He opened it and slid it over his modest member. It was lubricated so he began to slowly stroke himself, bringing himself to full mast. He closed his eyes until a dull heating sensation in his member started. He opened his eyes and looked down. In shock, he stopped stroking and gasped. His cock was now almost twice the size as before! It must have been 10 inches long now. He was shocked!
He watched in shock as his throbbing erection started growing longer and longer than before. His cock was stretching the condom quite a lot. Jack reached down and tried to take the condom off, thinking it would stop the changes. He found he could not take it off no matter how hard he tried!
In the mean time it kept getting longer and thicker. Jack noticed with some alarm that it was getting darker in color as well. What was going on? He had to stop this! His dick was over a foot long now. It was too much! He tried again with the condom when he realized that his balls were indeed much larger as well. They were about the size of baseballs, and the sack was a dark brown, and getting blacker by the minute.
Examining his cock he saw that it was almost black in color know. He noticed with shock that his head had flattened and become blunt. His genitals looked alien to him now. As his throbbing black cock pushed towards the two foot mark he noticed a thick ring surrounding his cock halfway down the shaft.
Jack saw as well that some thick black skin had grown at the base of his cock. It was all bunched up. Looking at the head it suddenly occurred to him; his cock was now a horse cock! The skin was his new sheath! The condom with the horse on it had given him a horse's cock!
Suddenly jack was overcome with a strong urge to grab his new shaft. His new horse balls were pumping huge amounts of testosterone into his system. He started pumping his huge shaft. He closed his eyes and bit his lips.
He came with incredible force, and he could feel the mammoth load traveling all the way up his huge length. He bucked his hips and he shot load after load. The load was small and white at first, before giving way to a thick, chunky and smelly yellow; horse cum. The condom lasted two loads before bursting open; there was too much for it to handle. Jack's flattened head flared as he kept firing. Without the condom he shot his load all over the floor and wall. It stunk terribly!
When his orgasm subsided he let go if his cock. Softening up, it slapped against his thigh and hung almost to his knees. The weight of it was immense. As it hung there it drooled thick yellow cum on the floor. Jack noticed a nasty heavy barnyard animal smell exhuding from his groin. This was nasty! His new cock was so gross!
Jack was astounded. He had a horse cock now! It was too big to fit in his pants. What was he going to do?! Should he try to hide his new appendage? Wear a different animal condom? Try to change back?