It's a question that has been asked since the beginning of time, or at least since sweating ended up being a thing: do mistress feet sweat more than other feet? The response, sadly, is that we just do not understand.
There have actually been no clinical studies on the subject, so we can just hypothesize. Some state that it's because mistress feet are usually covered up, so they don't have a chance to air out and dry properly. Others state that it's since girlfriend feet are normally in high heels, which restricts blood flow and causes sweaty feet.
Still others state that it's just due to the fact that some individuals sweat more than others, and there's no scientific evidence to support any of these theories. For now, https://dominatrixcam.net/mistress-feet/ to the concern stays a mystery.