Does she know you ride man? Buying shit for the bike, hitting track days, etc, are one thing...but damn, buying the entire bike?
There was a thread on here once probably a year back where some fella did that. Chick wasn't aware he bought the bike and didn't like them to begin with - something about past history not being good around bikes. Don't recall the turnout, but the consensus was the dude was a prick for doing something like that to her.
Hope she doesn't care you ride, and then well it's just a good laugh if the money isn't an issue. Hell, my wife buys enough ****ing shoes to outfit a small army, so I always figured that justified my track expenses. :fact