The undeniable fact of being a parent is that you have to reconfigure you're entire concept of who you are. Everything gets shuffled. Your sense of self gets ripped apart, inverted, and in every other way transfigured before settling into its new post-kid shape. So I get that a change in how you're referred to is, sometimes, in order. After all, your someone's mom now. But I have more than a few reasons why I wont' let my partner call me mommy, and they're all rooted in the fact that, well, enough has changed about me post-baby already. I mean, there's just something about the cocktail of hormones, sleep deprivation, and suddenly seeing your home cluttered with pastel-colored bullsh*t whose function you couldn't have corrected identified a year ago that all add up and result in you feeling like a stranger. You're a different person, and the person you are now is... in need of a shower, for starters.
With all of these changes come changes in little daily habits, too. Your sleeping and eating schedules are entirely different, your social life requires a great deal more juggling just to occupy a much smaller parcel of your calendar, and your freezer is full of a lot more breast milk and a lot less vodka. This is all fine — it's not like you didn't know parenthood would change things, and you implicitly invited that change when you invited a tiny human to set up shop in your uterus.
But with all the changes that you and your partner are understandably now tasked with navigating, I'm going to firmly put forth the idea that one common new-parent habit needs to die: new parents calling each other "Mommy" and/or "Daddy." Who the f*ck decided this was a thing that grown-ass adults need to be doing? Guys, this is a weird thing to do!
Aside from it just being weird and kinda creepy in a way that both can't and shouldn't need to be explained, here are some of my more concrete reasons why I would never, ever let me partner call me "Mommy." (Ugh, I feel unclean just typing that.)