here's the thing...
when you know something new yet a little not-right is going on down there...
#1) Don't look down. You kinda really don't want to know what is happening.
#2) Never talk about it afterwards.
#3) Don't date her for long... cause it's going to evolve into a freaky you're not cool with, eventually.*
Ignorance is bliss here. It's like kids pretending to believe in certain fat men in chimneys because they know the present gravy train will run out once they publicly wisen up. Just roll with it.
*I'd give it a 99% chance that a girl so astute in assplay this early in things WILL want to penetrate you with a strap-on. No doubt. I think many here will agree. Not a safe long-term bet there.