I'm going to be lighthearted about this as my bike ended my last relationship. (with a little help from my late nights and low tolerance for boss hoss)
Just tell her, "It's a baby bike, it needs someone to take it in. To love it, and feed it, and when it grows up to be big and strong, we can RIDE IT!"
Here's how my bike acquiring skills are;
Him: Where are you going?
Me: To look at a bike.
Him: Why do you need a bicycle?
Me: Uh, No a motor-cycle.
Him: What the f*ck are you buying a bike for?
Me: .........To Ride?
Him: What're you a dyke now? You're not keeping in
MY f&cking garage.
Me: Fine, I'll keep it somewhere else, but I don't wanna hear you crying about me being gone all the time, while I'm working on it.
Him: Just don't waste your money, don't get it.
Me: Piss off. Bikes before hos.
Then again, this is probably the reason I'll never EVER be proposed to.
Oh well, my bike loves me.
Hush, just send that nasty ol' 350f over here. I'll give her a good home.