S.W.
well i am probably not the answer you want - because i firmly believe that no spouse has the right to "forbid" another spouse to do something. Not only that but think about it - if yuo keep telling him no its goign to make him want it more- i said no for a lot of years and then i decided that it wasnt all my decision and so i told him to get one - we still dont (5 years later) have one i might add.
the other thing is this - yes lots of people do die on motorcyles, but lots of people die in airplanes, and in cars and on operating tables and riding bikes - but are you going to stop him from doing any of those things? probably not.
also the other thing to consider is: can you afford it? will this be in addition to his car - i DONT agree with fathers having vehicles that are too small or not right for their kids as their only vehicle. if its a 3rd vehicle it will save on gas. you also have to consider where he's going to be driving it - and there can be some "ground rules" associated with it: ie: no going above a certain speed; no snow; no racing etc - but as long as he goes to the classes and wears the helmet and drives safely then i say its fine.
hope that helps
S. w.