I prefer a partner's kids to call me by my real name. I mean, as far as they know, I'm just a friend of their parents. You start making your kid call them "Aunt" or "Uncle," and suddenly, the kids are like....why is THAT person special.... why is that person "Aunt" and that person not, I know they're not my real relative..... I so don't want to end up in a situation where the kids are used to that being code for "girlfriend" or "boyfriend"....then I come in and it's like, "Oh, right, you're the woman sleeping with my dad. Got it." Ick.