First off, for all of the pervs out there, I will be talking about naked sport bikes, not naked ladies.
@Demondosage have you checked out any naked bikes for your son? They are very much like your typical sport bike / rocket. But they ride more like a dirt bike. My brother, uncle and cousins all ride dirt bikes and we all have naked bikes. You sit more upright and your feet aren’t as far back on the rear sets. They actually have handlebars and not clipons like rockets. They are really exploding right now in polularity.
The Yamaha MT07, MT09 & MT10 will all perform similarly to a standard sport bike with more upright ergonomics. Sport bike in line engines.
The KTM Duke lineup is really great for people that come from dirt bikes to the street. They are Vtwin engines that make their power low to mid rpm. Only rev out to 11k. Really fun bikes. They make usable power low to mid so you don’t need to ride balls out to be in a typical sport bike power band. Try checking these out for your son. They make all different sizes. From a 390 all the way up to the 1390 SuperDuke R. A 790 or 990 would honestly be a great bike that your son would be able to learn on and still have fun on for years.
Almost all of the major players are making nakeds now, I just listed the the 2 I think are the top dogs.
Anyway, have fun and ride safe! It would be really awesome to be able to ride with my dad. Something your son will remember forever.