Earlier this year my 25 year old son came home and "surprised" me with his completion certificate from a local motorcycle school. They basically teach you the ropes in a local parking lot, and then you can take your certificate to the DMV and get your license.
Like you, I have been very conflicted about him riding a bike. The issue isn't him, it's the insane NY drivers who are maniacs with no patience whatsoever.
He has been going out with me since then, easing into it slowly. Good news is he rides within his limits and is being very responsible.
He bought a 1997 Suzuki Marauder (800cc) and owns it/insured it in his name. If he stays with it, he thinks he'll buy a Harley next - probably something like a Fatboy.