Question: how old do you have to be to get your nipple pierced?
Answer: There is no legal age of consent for body piercing, and so it's legal for someone under the age of 18 to have a piercing as long as they have consented to it. Children under the age of 16 can't legally consent to a genital (or in the case of girls, nipple) piercing, as it's considered to be indecent assault.