I just thought of something. There is a large number of teens who are having “safe” sex, where they cant get pregnant, by going anal.
Sooner than later, a pre teen boy needs some extra length. Trust me, as someone who isn’t long enough to effectively penetrate a rather plump hottie anally, it will come into play.
Of course 99% of teenagers dont quite have the booty my 40yr old wife has. But, she also had that same booty, and more when she was in high school. That’s when I met her. The girl was not skinny, ever.
She was in the 95% percentile of 16 yr old girls and about in the 75% of 40 yr olds.