Test pilots look at the top edge of the envelope as altitude and the right edge as speed. So pushing the envelope is Higher and/or faster. I am not a test pilot, nor do I want to be but I understand the concept.
In my CD realm my SO knows I CD but is not enthusiastic. I went to panties 24/7 a bunch of years ago [open the envelope]. The "underwear drawer" became the "panty drawer" a couple years later [push the edges some]. Lately bras have shown up there as well [expand the edges a bit more]. Couple other incidents [explicit details omitted] push a bit more.
Kat obtained a couple lace bodice camisoles recently and been underdressing a bit more, mostly with a Hawiian shirt as camo. Rather than wash the cami's in secret I put them in the dirty laundry pile to see where they'd end up. Call it an "expand the envelope" operation.
Results.. 100% success. First call was to check the T-shirt drawer. Nada. 2nd check the panty drawer. Bulls-eye, Center of Mass. Cool! 3rd would have been to check her drawers (it wouldn't be the first time she'd appropriated an article of clothing of Kat's as her own).
Give it some time and my dresses will hang along side hers in the walk in closet! (I also forsee an closet expansion project in the offing! the 5x5 walk in is woefully small!)
* in that case I'd let it be and go buy another from an different mfr for Kat. She generally understands certain brands belong to her and others belong to me. She wears Hanes and I do VS. Easy peasy.