This story takes place in a world where humans & anthromorphic animals aka Anthros exist. Anthros & humans live side by side as equals. Now anthros don't ever wear any kind of footwear (not even socks) because they don't need to. Actually most can't really. Also for Anthros clothing is very optional. So it wouldn't be odd to see one that's going bottomless or totally nude.
Now that's explained it's time to get on to the real story. Your mom or dad (or both) has hired in anthro to babysit you. The anthro is female. Your age can be anything from 4 to about 10 years old; but not higher. You are a boy or a girl (decide). You may or may not know this anthro previously. You and the babysitter have or will have a special thing you 2 like doing. It will be voring you which is nonfatal. Or unbirthing you. Of course your parents don't know the babysitter is doing either of these with you. And you are totally willing. She won't force either of these on you. Also the answer babysitter can also be taken care of other anthro little ones; anthro kids too while babysitting you.
The anthro babysitter can if you're willing age regress you. Also can transform you into an anthro too; a young anthro of the same species she is.
Noted she does not have permission for your parents to do this stuff.
So what species is your anthro babysitter? Do you previously know her or is she new to you? How old are you? And are you a boy or a girl?