He was born as a male child to Hermes and Aphrodite. During his travel to Lycia and Caria, he stopped by a pool where abeautiful nymph Salmacis resided. She immediately fell in love with the boy andtried to seduce him.
But Hermaphroditus rejected her. When he was about to takebath the lust filled Salmaci who hid behind the tree, came out and forcefully hugged him, kissed him and wished that she should never be parted from him forever. Her wish was granted.
Hermaphroditus lost his masculinity and became a person with both sexes, ie united form of him and Salmaci-first female pedophile.
The deranged Herma cursed the pool to turn any male who stepped into that to turn like him. His wish was granted too.
|Pic from here|
On another lighter note, in Kerala,ie in one of states in India, almost 90% of population has this naming convention. Every child will have a name formed from dad and mom like ie
Hermaphroditus - Hermes+Aphrodite.
But I am not saying that state may have larger number of eunuchs.
Moral of the story : Never say "NO" to beautiful women. If you are saying "NO" to a pretty one,it does go without saying that you are indeed a eunuch.
Check more comparison mythology stories here