-A sleepover for 3 friends that's either crashed by a predator, or they had invited an unassuming girl over who gives into her suppressed hungry instincts. Would go well with a chubby bunny for the latter idea.
-Prey gets sent to some weird gym, and find that it's only them and a big squirrel personal trainer. It's obvious she does a lot of squats, and s/he's likely to end up a post workout snack by the time she's done with her routine.
-Prey is supposed to spend the day working on an uncle's farm for being a brat, but discovers that he's missing and the only one around is his prize animal- either a hungry horse, a bottom-heavy pig, or cow.
-Hippo girl sets her eye on someone at the public pool, and either corners them in the deep end or the locker room to turn them into a snack
The predator having a prey best friend. It's a theme I've seen in a lot of artwork here, I think it'd be fun to do in an RP
Princess, deity, or other royalty has to marry but doesn't want to. She declares that anyone who would wed her must be able to survive a trip inside of her to get around it.
Serial killer/kidnapper who grabs people from off the street or uses dating apps to lure prey in, then leaves (almost) no trace of them behind.
Predator who just really wants to fill out her frame, either for narcissism or maybe to impress someone Maybe she gets addicted to the way vore feels or how her prey makes her hips jiggle.
Predators who convince their prey to be hesitantly willing or allow themselves to be eaten. Maybe sexually charged, or the prey is too curious for their own good
A magician on-stage, doing tricks and demonstrations involving vore and either assistants or volunteers from the audience. The vore and techniques would look more or less like magic to the viewers; Things like swallowing someone whole and passing them through the ass, managing to swallow/insert a full person without showing a bulge- or alternatively digesting/absorbing them so fast that it looks like a disappearing act. You could also do fun size manipulation tricks, then have the magician cheekily eat them or drop them down her dress/pants, lots of possibilities (came to me in a dream)
A predator that doesn't quite grasp the consequences of eating someone. She may get that the prey doesn't like it, and might even enjoy their struggles and feeling full, but doesn't understand things like digestion, or intimate/socially taboo ramifications.
Jealously or revenge vore. Predator eats another as the ultimate insult- indignantly shoving them in one of her holes and/or digesting them, and/or crapping them back out, and/or putting that rival onto her own curves.
Something where the prey is a little too energetic and rambunctious, fighting back. Pred would drop them down her panties or inserting them (front or back) and keep them in there for a while to humiliate and tire them out. Could go through a few cycles of checking and putting them back down/in there. Once they can't fight back enough to be a problem,
Catching a small human through some means and keeps them as a pet/toy/treat
Being/Coming under the possession of a Pirate-Queen esque girl for her own amusement. Slave/prisoner used for entertainment, to satisfy certain desires, satisfy hunger... i.e. someone with excessive power or influence with almost complete indifference you, her prey. Think Aria from Mass Effect or the Awoken Queen from Destiny
A princess rescue goes wrong when the princess wants her savior for specific things
Roleplaying a scene where two people are roleplaying, themselves (RP within an RP

)
Movie theater accidental anal vore. Trying to find an unoccupied seat in the dark can be challenging...
A girl and boy playing around with some way to change size end up taking things a little too far
Generic vore bar/strip club for all of your interesting desires...
Cavity search goes wrong
Someone is sacrificed to a giant goddess of some divine idea
Vore as a means of protection- maybe for hiding, protection from elements, etc.
Fantasy creature/Anthro/Neko:
An angel captures a warrior or rogue and either keeps him in her own hideout or brings him back to her society
A society where anthros/furries are dominant, and humans are treated like second-class, edible citizens
There is a park/amusement center/ zoo habitat (what have you) where people go with the purpose to face off against or run and hide from predatory creatures off any and all types. Can resemble an arena or an artificial habitat and have just one or many preys in the rink at a time. Can have digestion and death, or just be harmless fun.
A mermaid (and maybe a few of her friends) come across a human, maybe bringing him back to their city
Or, maybe a mermaid and a human meet in the water, with the mermaid trying to hide what she is
A lusty teenage naga finds a human and desires to have his child, then eats him to nuture it
A younger, smaller naga tries to catch and eat someone to show off to her friends
A very curvy Neko catches or lures someone to her and has her fun with him (Several instances of vore preferrable, same size or macro/micro)
Tiny people are found by a centauress, or a giant centauress comes upon an adventurer or a village
Harpies harassing, dive-bombing campers or hikers in the woods or mountains
An anthro fox or wolf-girl has a crush and special desire with someone and finds a way to live it out
An angel, benevolent or malevolent, has slaves that fulfill her every desire, even hunger and lust
Someone is caught by a playful Neko who may or may not be somewhat hungry...
An encounter in the woods between a playful but naive wolf neko and a passerby or adventurer
The princess is guarded by a dragon, but the dragon might get hungry... (Either the princess or maybe the rescuer as prey

)
Pokemon:
Trainer and/or Pokemon getting overwhelmed by what they thought was just a normal wild Pokemon
Gladiator-style Pokemon battle with Arcanine, Seviper, Ekans, Charizard, etc. (Big or powerful ones)
Animals:
A horse gets tired of her regular diet and wants a bit more meat, and perhaps some enjoyment as well.
Possibly not your average horse, maybe one with the ability to communicate, shrink and grow people, or maybe even grab things with her tail, such as to move things behind her.
Using farmyard or zoo animals as a way to punish/degrade/get rid of a rival, bully, jerk...
Hippos or panthers catching up to safari-goers
A dragon captures a wayward soul, either for slavery, pleasure, food, or all of the above
T-Rex or other large dinosaurs in the zoo either get out or are lucky enough to have someone fall in