Got any ideas for the reverse? Human whumpee and non human whumper?

For sure!

Fae Whumper who toys with a human. Maybe they pretend to love them, they're special, they do everything for Whumpee! Until they're done, and they tell Whumpee it was a game, and now they're bored. Whumpee is left alone, heart shattered, feeling like nothing but an object.

Fae Whumper who kidnaps Whumpee. They're a plaything. Maybe Whumpee has a skill, music or dance, and is forced to perform until they 'break'.

Dragon Whumper who demands a sacrifice. Whumpee is brought to them for this. Maybe Whumper kills them, maybe they keep them as one of their treasures. Whumpee is a prisoner for life.

Robot Whumper who loves to experiment. They implant a mechanical control in Whumpee, on their spine, to control all their limbs. It hurts like hell, but Whumpee can't even scream.

Mermaid/siren Whumper who lures Whumpee in, only to grab them and drown them.

Alien Whumper kidnapping Whumpee to do research. They're fascinated by Whumpee.

Good old Vampire Whumper, using Whumpee as a blood bag. Giving them a good life or the bare minimum, whatever they prefer.

Demon Whumper playing with Whumpee, terrifying them, torturing them, haunting them, tempting them to do evil...

God Whumper demanding sacrifice or eternal worship, demaning more and more, feeling entitled to Whumpee's life. Stripping them from everything, just because they can.

Maybe they thought about restraining whumpee, but the struggling would reopen wounds. Or they thought about sedating whumpee, but the sedative would interact negatively with the plethora of other medications whumpee is already taking.

Whumpee:

“It’s not as bad as it looks, I swear.”

“Can I just sleep for a little while?”

“You can’t make me go to the doctor’s. I’m fine.”

“It still hurts.”

“I don’t need that, honestly!”

“Everything’s…spinning.”

“Could you stay with me til I fall asleep?”

“Why am I so cold?”

“I feel better already.”

“Just make it stop, please.”

Caretaker:

“Easy, I’ve got you.”

“I don’t care what you say, you’re having the day off.”

“You look tired, Whumpee.”

“Does anywhere else hurt?”

“Just get some rest for me. You need it.”

“Take it easy today, you still look kinda off.”

“You’re not making any sense, love.”

“Well, medicine doesn’t usually taste great.”

“I promise it’ll all feel better in the morning.”

Like all they can do is scream or cry, it hurts so bad they can’t even form words. They might be shaking or hyperventilating, breath hitching if another wave of pain hits them. They can’t stop the tears flowing down their face. Caretaker/team tries to soothe them but nothing works—they don’t even respond.

Or, maybe they do, but its a quiet, pleading “please, make it stop,” between cries. Maybe they beg. “Just shoot me.”

Caretaker stepping in front of whumpee instinctively when there's gunfire/a loud noise/etc.

Whumpee looking towards Caretaker instinctively when faced with danger or a difficult question.

Caretaker carrying whumpee's belongings for them or opening doors for them. Generally making tasks easier for whumpee.

Caretaker knows things about whumpee's recovery or medical situation off the top of their head, without even having to think about it.

Or Caretaker gets defensive when asked about whumpee. "Why do you want to know? What do you want with them?"

Whumpee leaning against Caretaker's shoulder when they're next to each other.

Caretaker lightly brushing a hand against whumpee's hand in a gesture of comfort. Or whumpee initiates that, and Caretaker picks up on a hint and holds their hand.

If the relationship is fated or somehow bound, there may be markers of a unique bond, such as tattoos, bite marks, etc.

Their tone of voice changing completely as soon as they start talking to each other. Maybe they're shy with everyone else but joke with each other. Or maybe they act cheerful with everyone else, but turn serious as soon as they can talk to the one other person who knows what's really going on.

Nonverbally checking if whumpee is okay with meaningful glances across a room or "thumbs-up versus thumbs-down" gestures.