Your kitsune would say that she didn't know much of the engineering and blacksmithing behind it, but she was aware that it was a method many artificers used to create certain enchanted weapons and armor.

Speaking of such things reminded you of the armor Bertha was making.

A certain busty Warrior of yours had made some armor for your wives, and was now in the process of showcasing it to you and Gerty. Your Holy Knight was here to help Bertha make armor that would suitably stand in for Gerty's original Holy Knight's Armor.

It ended up with mixed results. It wasn't exactly a failure, but design was... interesting, to say the least. Though it was a bit ridiculous with how much space it gave by the stomach.

"This isn't the final version." Your warrioress began. "Like, it can be kept this way I guess, but this is just as an example cause it isn't even enchanted. I'm gonna be looking at enchanting something in the gear I make so it can instantly fit and feel comfortable no matter how big any of us get." She looked determined to do as good of a job as she could, though it was still clear that this wasn't a passion project of hers. "I was also gonna work on that eastern armor thing that Ayane wanted. I've never really made 'samurai' armor or whatever its called, so it should be fun." And after answering a few questions, mainly details about the materials she was gonna use, she left.

"Master." Gerty said when Bertha was gone. "The armor feels airy." Gerty then tapped the comically large part of her metal 'stomach', a hollow echo resounding.

"Well Bertha said she'd fix it later." You reminded her.

"That's not what I'm referring to, sir." Gerty continued. "There are parts that, while not terrible, feel more like enchanted Adventurer Armor in than Holy Armor."

"Are you complaining about Bertha's hard work?" You chide.

"I'm-"

"You will go around in your underwear since you hate it so much." You finished.

"Sir, yes sir!" She saluted and began to strip.

Clenching her fists when she was done, a furious blush spreading across her face all the while. Given her fierce and unchanging expression, one might've easily mistaken this reaction for anger. But you knew her better than anyone else. Little cracks upon her countenance began to show, her masochism revealing itself the more you bossed her around.

Despite Herta's influence, Gerty still wasn't much of a exhibitionist. Although she'd gotten more comfortable with you feeling her and using her as you wanted while in front of others.

Yet a constant remained in how she was willing to publicly humiliate herself for your sake and for the sake of her duty. This could easily be brushed off as her being a good slave-wife, but you realized this was just her love for getting abused badly hidden behind a layer of formality. Further proof of her masochism was her carefully honor threatening to crack the more you harassed her.

Still she would never break unless you openly declared your intentions to her.