Hmm, in the time period of Europe that these fantasy settings are usually modeled after, the age of sexual maturity is considered closer to 12-13 due to puberty really kicking in and the menstrual cycle beginning. But even by those barbaric standards, 5 years old would be considered the same as raping an infant. In many European cultures at the time and at least backwards into greek antiquity, there are only two stages of life: child and adult. There is no inbetween stage. So until you hit marrying age, even your gender didn't really matter, and you were seen as a sexless child. Many cultures dressed boys and girls the same until that 12-13 year age. So having sex with a 5 year old would be a scandalous and horrifying act, even to your average thug, who would have no issue assaulting a 13 year old. But in his mind, a 13 year old is a "woman"; A 5 year old is a "baby".