In high school, I had both my parents as teachers.
Sounds like ready-made trauma, right?
But, you see, when you grow up knowing that a. your parents are teachers and that b. if you take certain classes you'll have them as teachers (because they are the only people who teach that subject) then it really isn't much of a surprise. I mean, by the time I finally got to their classrooms, I'd known it was coming for over a decade.
So, you know, I did have a little time to prepare.
I didn't call them Mom or Dad in class (because, ewww!) and they treated me just like they would any other student (they'd had time to get ready for it too, after all) And that was that.
Now, if you want to talk about my mother telling me I didn't need to take typing because "it wouldn't be that useful," well--that's another post altogether :-)