Was feeding mice to a "cartoon wolf" (not any from real life as far as I remember), their butt and pussy was being stuffed with prey, but suddenly it was not there after turning away to get more prey
from the box next to me. The prey inside them was still there making sound but they were trying to crawl and push out of the hole that was no longer there... The predator loved it and even pawed at the spot
where the tiny bulges were pushing. "Oh good, at least I got something stuck in there before I lost the chance to feel (put?) anything ever again down there!" At the time I was mad I couldn't keep feeding them or end up joining the prey as a big insertion, I missed my chance. After I woke up I remember what they said and realized what they meant... instant boner lol. Basically they got the chance to fill a hole that normally isn't there (or doesn't exist) and now that it's "gone", whatever is in there HAS to be there regardless that it is gone, now they can feel pleasure from a hole that is no longer there and the poor insertion is trapped forever on toy duty. Oh yeah one more thing, the butt had 1 prey still sticking out but once it was pushed in the hole, it shrunk tightly around their form, until they where fully out of view the hole was gone along with them. Like a weird hammer space that was collapsing and closing up for good, but in this case it was the holes size and scale being changed and warped by the prey (or it's contents) rather then the prey being hammer spaced into said hole or space. The hole only existed as long as the entrance was still stuffed, but once the space was clear, SLURP gone. Sealed tight no chance of being in sight ever again trapped under the flesh and fur of the predator.

From what I got from the dream basically when cartoon characters that normally don't have gender bits or butt holes suddenly do....
However what if they only had them for a short period of time? A spell, love potion, appears only when being in the real world or outside their own...
What if suddenly against their own desires or after climax said new "holes and goals" vanish or seal up.... with prey still inside?!

Taking the concept of null bulges or lack of gender bits being "unlocked" for awhile, letting prey slip inside those areas, but what would happen if it went away? (sealed under flesh)
Prey perma stuck inside a hole that no longer exists, no exit, fated to be trapped in a place that is "still there" but is no longer seen or physical accessible to the "outside world" of the predator.
Cartoon example: You get to stuff scooby do, you get anal vored but then he has to return to his show. The backdoor disappears but your in his butt... but it can't be there it's not there, but your still in it!
They got you trapped in the deep end but the exit is just gone, nothing but a sealed up tight hole with no exit. Now they can still enjoy feeling you there up their butt and now you can never leave.
Just a butt toy for a butt hole that no longer exists. Trapped in a null butt never to escape....

A bit of a confusing mess but I got the idea from it... Basically for now calling it SUF for sealed under flesh, a play on the word snuff I guess. (but in a way that's truly not fatal but yet still not good for it to happen to you! As you be perma trapped in your place.) Or perhaps "S.T.U.F.F.E.D" could work: sealed tightly under faded flesh entrapped and doomed!

Also just imagine you where fucking some one that was about to seal their hole with a null bulge and as your dick slipped out and you went to thrust again but you just slam against a flat wall there...
Or it was sealing as you had your dick in there so you feel the tightest hole ever, but once you pulled out you would never get the chance to feel such a tight hammer spaced hole again as it sealed up.