This age is usually the beginning of puberty, and followed by a new addition on the upper lip.A magnificent, yet awkward weird soft fluff moustache.
which is the bar mitzvah moustache.
One can be defined with having a bar mitzvah moustache regardless of his age, religion and sexuality.
"that girl thinks no one sees, but she clearly got a weird bar mitzvah moustache going on"
"I'm sorry guys, can't join movember, my bar mitzvah moustache doesnt want to normalize regardless of the amount of times i shaved it"