It's possible there's supposed to be, but it got hooked up wrong.
Vark's GitHub page if you (or anyone else) wants to try to figure out what's going on.
I was already looking at that to come up with an answer when you posted that. The GitHub is six months out of date, but I doubt Vark's contents have been touched in that time.
Really hoping for some kind of update on this, still have not been able to find any kind of way to resist. "Leave" and "Question him" are always grayed out.
The Leave button is only disabled if he's already punished you for teasing (i.e. you've already seen the scene you're looking for), and the Question Him button is disabled after taking that option but is re-enabled after getting collared.
To get the punishment scene for leaving, you'll need to leave without fucking him three times in a row, regardless of if you've been collared or not, and it'll trigger on the third time. If you're sure you haven't seen that scene before, go to the room outside his cave. If you have seen that scene, then there'll be text to the effect that you won't have the option to leave: either
After {another/a} brief pause you remember that you won’t have a choice in whether or not he punishes you after the way you roused him to act.
or
You bite your lip, knowing that if you go in, Master will have his way with you.
If that text doesn't show, you should still be able to leave; if you still can't, then it must be a bug that's been introduced since the GitHub was last updated. If it does show, the only way to be able to leave (and thus access that scene) is to save edit the flag VARK_PUNISHED to undefined (in TiTsEd, this means selecting the flag, then clicking the red X at the top of the flag list).