I was married when I bought my motorcycle, do you think I asked my wife's permission?! Hell no, i'm not a 5 year old baby that needs mommy's permission. She came home one day and BOOM, motorcycle in the garage and I said 'Oh by the way, i got my motorcycle license today".
If you have a partner that doesn't support fun things you want to do, then she's not a good partner. it's not like you're doing something bad, illegal, dangerous for your health, etc. my wife HATED motorcycles too, I got a ZX6R, after a few months she had her own gear and I was giving her lifts too and back from work. Your wife will do the same, trust me.
You're an adult, go do what you want to do sir.