Slave Princess

You are the king of a small kingdom located in the south of the continent. Recently the king of a neighboring kingdom much larger than yours declared war on you with the aim of annexing your territory to his. However, you were a peerless strategist and soon managed to take the enemy capital city. You threaten to loot and destroy the city along with the inhabitants. But then the enemy royal princess appears before you and, bowing, offers to voluntarily become your submissive slave in exchange for you sparing the lives of the citizens, something you gladly accept. How will you treat your new slave?