My 18 yr old and I made his 1st trip to M/B bike week this year, THAT was cool, and just got back from the Dragon last week which by the way he rode (and Loves)the speedy through the Dragon, Cherohala and the ****** bender, (did exelent) I took the Dyna.
Hes been ridin 4 wheelers, mini bikes and dirt bikes since he was 4. I taught him how to ride street on a 700 Virago (wifes bike) and he was ridin my Harley when he was 16. Hes got a 94 800 Marauder now.
Its cool cause he has no desire to get a crotch rocket, he likes cruisers.
All you can do is teach them the best you can, and hope it sticks with them. I harp on the saftey stuff as much as i can with him.