LOL!
Really, simple next move is to bring the bike(s) inside the house. Too many bikes in the garage? OK, how about one in the bedroom? One in the den?
I think she'll get the message. Not seriously trying to tell you how to go about this, but generally, to keep the peace, she should stay out of the garage, as guys should stay out of their closet. The number of bikes may be sign to her you're not going to be spending enough attention on her. Keep the romance healthy and she'll allow you to open a bike shop.

I'd keep both, tidy up the garage (more space for you, NOT her stuff), take her out on a romantic evening, and set up the MB-3 for your goals. It's the better choice.

alternate solution: build a bigger garage!

PS> I have 12 bikes of my own, 10 are in project state and boxed. Kids and wife just picked up 4 mtb fixer uppers for themselves. One is going straight into the trash. And she recently picked up a Ti mtb frame that she thought I might find interesting. My 3-car garage is a very packed place. I give no unsolicited opinions on her number of shoes or handbags.
Works for us!