Transfiguration

The curse was something you were certainly not looking forward too. Transfguration was very serious but you had no idea what this was leading to or meant for...

You bound naked in a spell circle designs painted to your flesh while the mage explained to the prince the purpose of the spell. "So this is permanent, your **** will not develop into a man but rather take on more feminine features... but will not be a woman without some serious spellcraft... you'd have to find a witch or Sorceress for such a spell." The prince smirked at you and shrugged his shoulders as you shivered in fear.

The spell was cast and over the next few years your features did round and soften, you 'male' qualities fading with every year. The prince mocking that appendage between your supple thighs, he refused to refer to you as anything but an it. Though the prince certainly had his fun at your expense.