The odds of the tween boys getting the message you think you're delivering is quite low.
When I was a kid we walked to school. 3 miles. In a blizzard. 20 below zero. Uphill both ways....
And we didn't even have to.
Honestly, don't be disheartened... the message will still be delivered. It will just hide subliminally, for years or even decades, until it pops up and delivers the payload. Lead by example, nevermind what the tweeners make of it today :-)