Like… In my opinion, a hole is when it does not go through, and when it does, it becomes a tunnel. A straw is a tunnel. A hole in a piece of paper is a tunnel. A bowl is a hole.
Allow me to introduce you to the concepts of “blind holes” and “through holes”…
Personally, I think “butthole” sounds more pleasant than “butt tunnel.”
That’s because you’ve only named one end of the tunnel. It’s the Mouth-Butt Tunnel.
Indentation: “Am I a joke to you?”