How does this outfit look on a boy?

Your Nike link didn't work, and it depends on the graphic on the tee. The cargos-and-sneakers look is really average, though, and won't stand out at all, especially from AE. If the shirt has a brand like Aero, AE, Hollister, etc. on it, don't wear it; everyone wears those and it looks tacky. It really does. Try a striped oxford or cardigan with the sleeves rolled up over a tee from Threadless or Urban Outfitters.