The same reason girls whine at the age of 9. Because they're 9.
The Fabulous Beekman Boys - 2010 Food and Whine 2-4 was released on: USA: 5 April 2011
About 9 for boys and girls
9
for boys in the age 5-9 it is but not for girls
Miami Monkey - 2013 Whine Bar 1-9 was released on: USA: October 2013
Girls reach puberty earlier than boys at the age of 9-12 years. Boys reach puberty at the age of 12-14 years.
Most boys can't produce sperm at age 10. However puberty is a very variable process and the normal range of ages at which boys start puberty is from 9 until the late teens. Ejaculating sperm is not usually the first stage of puberty but some boys who start puberty at age 9 may be able to ejaculate by age 10. There is also a condition called "precocious puberty" which starts the process of puberty in boys who are younger than 9 years of age. So, although most boys won't be able to produce sperm at 10 there are some boys who will be able to.
Whipping boys were usually of a similar age to the prince to whom they were assigned, and held their post throughout the prince's period of schooling, which could be from the age of 8 or 9 right through to age 16 or 17.
Tia and Tamera - 2011 Too Much Napa Whine 2-9 is rated/received certificates of: USA:TV-PG
8 and Under Girls 8 and Under Boys 9-10 Girls 9-10 Boys 11-12 Girls 11-12 Boys 13-14 Girls 13-14 Boys 15 and Over Girls 15 and Over Boys
You can be anywhere from age 8 to age 18, there is no set age. I am 10 and started masturbating when i was 9 and i now ejaculate daily.
about even but girls are taller at age 12 or 13