I think that hes old enough to not do something like that bc someone else liked it... Im sure hes doing it because he liked it!
I woudn't worry... hair is versatile, if he gets comments or told by someone that hes too old for it, then the next day he'll have it dyed back to normal color and Im sure combed down and not spiky til it grows out.
I wouldn't worry about that... its HIM who has to look in the mirror.
Im constantly telling my mom she needs to emotionally seperate herself from my brother. My brother is almost 30 and going on 13. Hes very needy and tells her she is his mom, like at 30 he needs a mommy???? Anyways, bc of his neediness he kind of forces her to take on his problems, hes always running to her when he has problems. Its sad really! She moved from new hampshire to New mexico and it took him less than a year to follow her. Anyways, I guess you don't want to see your son make a mistake or whatnot, but on the other hand, some lessens (esp this small) are meant for him to learn first hand and you not to even worry about