This Maybe A Stupid Question.

This maybe a stupid question but... when do you grow hair under your armpits? LMFAOOO.

Can range from 11 - 17, depends if your fast or slow. I started getting some a few months ago and I was 14 at the time :)

Different parts develop faster than others, for example someone may get hair on their chest before their arms.

When you start puberty....

if you concentrate really hard, hairs will grow under your arms.
nah, view the wikipedia article here for more info.

Hair under your arms is a pain in the bum :@
Don't use roll on deodorant when they show up :P