WOW, for something that big I'm thinkin you need to start with a good bottle of red wine at dinner then drop the bomb supported by some marginal rationale like its part of “our” warranty requirements, or maybe “our” insurance company will give us a discount for any items stored in a secured space,,,
Then maybe off-set it with some short discussion about getting something for her, or maybe suggest a generic trip to the outlets,,,
Well thats one possible approach,,, LOL
Best of Luck
p.s. remember “liquored up” = coherent and agreeable NOT passed out and doesn’t remember anything! Its gotta stick later or the deal is off,,,