She might take up the tactic that my intended uses - "Oh, let's go shooting together!" It might sound like fun, but how can you resist her desire to use the Zeiss and leave you with that APS relic she found in the trunk of the car? Remember - resistance is futile.
It gets worse. Suddenly, she wants to know why you're in a bidding war over a Bessa II when you've already got the Zeiss and "I could use more film for it, oh yeah, and some filters". I've been OKd on buying LF - as long as it is an FKD for me and a Toyo with a bag bellows for her. I get to carry the Toyo whenever she shoots.
No, it's not the worst of all possible worlds by a long shot - I've never heard a complaint about buying decent film, of B&W - but if your better half goes this route, prepare to move over. Working out a little so that you can carry two of everything helps too.