My first Shizaya fic with the help of my partner magicalgirl10059~ I hope that you like it!

Oh god… I'm screwed, I'm screwed, I am SO screwed… Shinra thought as he stared in horror at the sight by his feet, or more accurately, around his legs.
What have I done? Oh my God, I gave him the wrong...
"Mrow~"
…Cat DNA! How in the Gods name did I even come to possess such a thing! I've screwed up past the point of no return.
"O-okay little kitty-kitty, get off my legs…now, please." Shinra begged, making feeble little kicks which did nothing, but he kept trying anyway, only to lose his balance and fall.

Crash

"Ugh…" He groaned while rubbing his backside.

"Mew~…"

Celty barged into the room ready to aid Shinra at the clattering sound that resonated from the lab. [Shinra! Are you-]

…

…
Celty stumbled back a little, and who could blame her, after all? You'd be hard-pressed to find someone not freaking out over a mewling, purring... Izaya Orihara. Complete with furry black ears and a sleek tail to match. Instead of circular pupils in his ruby red eyes they were slim oval slits that resembled a cats'.
Celty's fingers shook a bit as she typed on her small key pad. [Shinra… by all the seen and unseen Gods of Ikebukuro, tell me that is NOT who I think it is...]
The newly half-cat informant seemed to take an instant liking to Celty.
"Mrow~!" he exclaimed loudly, launching himself into her arms, where he further wrapped his around her neck and nuzzled her helmet, a loud purr rumbling from his chest.
Almost immediately Celty's arms shot out, but she hesitantly patted Izaya's back until it settled into a light petting motion that made him shake with pleasure at the comforting sensation it brought him. [Aw, Shinra. He's so cute!] If she could, she would have squealed at the adorableness that clung to her.
"Uh…yeah," he muttered, getting up and dusting himself off. Being that he was on the floor the whole time just starring. "Did I mention that that was totally unintentional?"
(But-but-he's…oh my god… he's going to kill you!)
"Yeeeah, that was my reaction too..." He replied sheepishy.
[What's going to happen when you change him back?] "If I can", He corrected.
Celty turned to him in confusion, denying the realization that grew in her. [What do you mean if...]
"I... I might not be able to change him back..." The underground doctor admitted.
Celty's heart beat picked up. [Shinra, what are we going to do? There's no way he can stay like this forever!]
"I know that, Celty! I didn't even know I had this stuff! I would never have done this on purpose! Okay, maybe I would if it was…" He trailed, imaging Celty with a full set of pure white cat ears and a tail. He drooled at the image.
[Shinra, you pervert!] She jabbed him with her elbow, sticking the key pad in his face. He recoiled. [Be serious! Do you realize what's going to happen to him? He can't even talk! He's just purring and cuddling! What do you think his clients will do? There's no way he can protect himself like this! Just look at him!]
At that moment Izaya choose to shake loose from Celty's hold and climb over to Shinra, nuzzling his leg. He licked the doctor's hand, sensing how nervous he was and trying to comfort him before he went back to Celty. Shinra paled, never having thought of that obvious bit, he stammered trying to come up with an answer. Izaya went back to Celty. "Oh boy…um… well... uh..."
[Shinra, why didn't you check, to see what you were injecting him with? You know you have millions of different shots retained in their vials! Why couldn't you have been more observant?]
"Celty dear, like I said before, it was totally unintentional! I was actually experimenting to see if I could duplicate Shizuo's strength but in him!"
The second the words left his mouth Shinra cowered back, readying himself for another one of the gut destroying quick jabs. But it never came.
Just in case he shouted, "He made me!" Instead of Celty harming him, she just stood there, rigid and shaking with a 23 year old man-cat latched onto her.
[Shinra…that's it! Shizuo!] She typed fast, jumping a little out of joy, almost knocking Izaya off.
"W-what do you mean?" Shinra asked, still prepared for the punch and shocked it wasn't coming yet.
[Shizuo can watch him! No one will be able to hurt him if the most feared man in Ikebukuro is with him. Izaya will be totally okay!]
"Celty…that would be a fantastic suggestion, except for one teensy-weensy little fact: Shizuo hates him and I'm not just talking about the fact he doesn't want to be around him but the blatant hatred that protrudes from his very soul! The one that makes him chuck vending machines and go on rampages in which he destroys the city! Do you remember that?"
[W-well, yes, but he may take pity on him if he sees how he is! Plus Izaya can finally be happy with his love!] Her body shook with a silent giggle that was until she acknowledged what she had just told him.
Oh, if only you could delete words, typed or otherwise…
"Celty…I believe I'm going blind," Shinra said, vigorously cleaning his glasses. "I think I need some serious new lenses. I could've sworn you called Shizuo Izaya's 'love.'"
Well, I've already let it slip. There's no reason to hold back now, the Dullahan thought.
[It's true! I know for a fact, he told me. He wasn't lying either, I could tell! He's loved him for years and years! Ever since they first set eyes on each other, his heart has burned like fire for him! But Shizuo heartlessly spurned him and discriminated against him! Every time they fight, Izaya goes away and cries! He's got photos of Shizuo on every surface of his room! All he wants is for Shizou to love him back.]

…

…

…

"Celty…I am 100% positive I could have continued life without knowing that."
Celty shifted. [...He doesn't actually have pictures, but Shinra, it's so romantic! It's true love! Come on; let's just give it one shot! If they actually fall in love, the fan girls will be satisfied, the city repair teams will have a lot less word to do, and I get 600,000,000 yen! Everyone's a winner!]
"What's up with the 600,000,000 yen?"
[Me and Namie-san made a bet about the two's relationship.]
"What on the God's green earth! How long has this been going on, my Celty?" How come I've never noticed this attraction?
[Shinra, please! You can't say that they wouldn't look cute together.]
The underground doctor exhaled loudly; sighing. It eventually turned into a slight smile, "…All right, Celty-koi, for you anything."
Instead of punching him for the lover's endearment, Celty hugged him, dropping Izaya in the process. [Shinra, thank you. Thank you. Thank you!] She typed avidly before sprinting out of the lab and into the living room area, shutting the door, Izaya in tow.

"Yes!" Shinra whispered loudly, fist pumping the air, noting that the room was not sound proof. "My love hugged me! Me! Oh, joyous day!"
Forgetting everything but his crazy exhilaration, Shinra whipped out his cell phone and called Shizuo, thrumming his foot excitedly.

Beep

"Yeah?", a gruff voice inquired over the phone. His ecstatic mood demolished some at the aggravation he sensed.
"Shizuo." Shinra said, tone attentive. "I've got a little favor to ask of you…"