Ah okay. Main problem with that is how much work would be involved and how complex the script will get for that sort of thing. It's unfortunately just not viable.
You can get living underwear without female partners on! Specifically, if Marin is off limits to you, the shop of horrors will sell it to you directly. Right now, it's only handholding I think that's out of reach for players that don't like female partners (and that hopefully won't take too long to change, though tbf, only girl npcs have handholding scenes at the moment anyways.)