Disclaimer: I own nothing except an overactive imagination and way too many plotbunnies.
Modus Operandi
Salieri doesn't like Blaine.
Kurt doesn't notice at first, because Salieri is being, well, Salieri. He always hides when someone comes to the loft, always. Even when it's Kurt, or when he's with Kurt.
It had only taken Salieri two days after officially moving in to develop an MO: when the doorbell rings, or the door to the loft opens, Salieri hides. If it's someone he likes, or if he becomes curious, then he comes out. If not, he stays in hiding until that person leaves.
(And if Kurt's blaming Rachel, and some of her visitors, for this development, at least he's not doing so out loud.)
As for touching him... Safe to say, Salieri is really picky about who gets to touch him and who doesn't. He'll allow Santana to stroke him for a minute or so, but Rachel is limited to ten seconds – and only when bribed with food. He won't get within ten feet of Brody.
It's become a joke with some of Rachel's friends that Kurt doesn't really have a cat, just food-bowls and a litter-box for fun. (Kurt fails to see the joke, in any of it, but. He keeps quiet to keep peace in the loft.)
People who stay long enough do tend to see a streak of black fur though, as Salieri races from Kurt's "room" to the litter-box, and then back.
When Kurt's dad shows up out of the blue for Christmas it takes Salieri five minutes to decide he's worth checking out, and then another two to declare him worthy of acting as a cushion. As Kurt walks out the door to go retrieve his mysterious gift his dad's watching a game on the couch with a lap-full of purring cat. It's a nice sight.
There's no sign of Salieri when Kurt returns, Blaine in tow. Which is as expected. Now, the question is if Salieri will come out again, and if so how he'll react to Blaine. Kurt will admit to being very curious about the answer.
The twin yowls startle Kurt out his cooking zen. In two months he's never heard Salieri sound like that, and why on Earth is Blaine screaming as well? He drops everything to run, only to come to a stunned halt when he sees Blaine storm towards him with his hands held out. His scratched and bloody hands.
"That cat of yours is a menace! A monster! Look what it did!"
Wait, what?
"How can you live with that running around? You should take it to a shelter or something." Blaine looks down at his hands, muttering "I'm going to have to find a doctor, aren't I, that thing probably has all kinds of diseases."
"Blaine? Are you saying Salieri scratched you? Because he's never done that before, not to anyone."
And no, a couple of small scratches when Kurt got Salieri unstuck that first day doesn't count.
"Yes. And I find that hard to believe, considering it attacked me at once."
And that just makes no sense. Salieri doesn't even show himself to most people, and he didn't even come out to greet Kurt, so why would he come out only to attack someone he's never even seen before, completely breaking his MO?
"How? I mean, honestly? How did you even get close enough to him for that to happen in the first place? Salieri tends to hide from strangers."
"I went to look at it, obviously. To say hello or something. After all, I have no intention of staying a stranger. So, I wanted to see the cat, let it get used to me."
And that makes a little sense, sure, only the thing is, Salieri's hiding place? It's a nest underneath Kurt's bed, created from a cardboard box and old blankets. There is absolutely no reason to believe he'd have gone anywhere else.
That means Blaine had to have gone into Kurt's private area, had snooped around until he found Salieri, and then reached in to grab him.
And that simply isn't okay.
"So what you're saying is that you invaded Salieri's safe space – and not just his, but mine too – and tried to force him out, and that's what got you clawed up."
Blaine opens his mouth, to protest presumably, but Kurt's not here for that.
"You still haven't grasped the concept of respecting boundaries, have you? Why am I even surprised? If you treated a human being the way you just did Salieri, they'd hurt you too.
"Just, don't. This is my home, mine and Salieri's, and you're a guest here – an uninvited one to boot. I'm not going to kick you out, not now, but you need to show some respect. Stay out of my private space, and stay away from my cat. And Blaine? Don't ever pull something like this again."
He doesn't just mean the invasion of privacy, and the manhandling of Salieri, but the whole visit. For the sullen looks directed his way Kurt's pretty sure Blaine gets it.
That night Kurt curls up not with his ex – as he's sure Blaine was hoping for – but with a purring Salieri. As he falls asleep it's with a new resolve burned into his mind: to never get involved with someone who won't respect his cat.
~The End ~