As his body expanded outward, more and more of his appendages reformed into overly long sexual organs. He even started to see new ones growing out of the larger longer ones. Every part of his mind was on fire. Pain and pleasure were the same thing. In moments he was pushed upward as more grew out from beneath him. He tried to push himself up, and he failed. He slipped, and dove into the water again. This time, he didn't try to get out. He couldn't even figure out how to do that. His arms and legs were tangled in his own growth.
In moments, he struggled to breathe. More water rushed into his body. The transformations continued. His eyes were almost instantly blinded as grows erupted all over his face. His bones were softened and reshaped. What last resembled a torso in the midsts of the swirling growing mass of long sexual appendages were reshaped and separated. Even his mind was pulled apart.
Then in one final moment of total climatic ecstasy, the last bits of connecting tissue broke apart. Hundreds of the individual organs of varying sizes swam off down the river, each with their own need to feed and breed.