Credits to SecretJonatelloShipper
Summary:
Casey gets turned into a vampire by accident from one of Donnie's experiments now he has to release all these new... Instincts~
Casey... Didn't know what to make of this, he sat on the chair as he watched his boyfriend frantically ran around the lab in a state of panic.
"Oh fuck! Fuck!! How could I be so stupid?! I never should've kept that vampire DNA!" Donnie shouted, he was checking Casey's blood on his microscope, bending over slightly.
Casey stared at his ass, he sniffed the air as he could practically feel Donnie's blood rushing, he licked his lips with a grin, "Hey... Don't worry about this, Babe... This ain't so bad~"
"Casey, you are a vampire, a mythological creature known for feasting on blood and other living creatures! How is this a good thing?!"
Donnie rubbed his temple as he leaned against the desk, he jumped a little as Casey wrapped his arms around his waist and kissed his shoulder.
"Because..." He licked his all over the side of Donnie's neck, enjoying the way his heart raced, "Now... I can fuck you and feel how your delicious blood races just by my thick cock in your pretty little body~"
Donnie turned bright red and he turned towards Casey, "C-Casey, we... We can't" he gently pushed him away, "Not with you like this, it wouldn't be right, we have to cure you-!"
Casey pinned his arms around Donnie, allowing him to place himself between his legs as he pushed Donnie onto the desk.
"Oh come on~ I can tell you want too, I can smell it..." Casey hissed as he kissed that sweet spot on his neck, "I can.. Feel it~" He grinned as he rubbed his inner thigh.
Donnie blushed as his legs began to quiver, "Oo.. Ooh~ C-Casey" He leaned back as Casey continued pampering kisses on his neck, he looked up and saw Casey's smug grin with... only looked more attractive with his new fangs and piercing blue eyes.
"So~?"
Donnie bit his bottom lip and covers his flushed face, "B-Be careful not to bite me, okay?"
Casey grinned as he stared at the flustered turtle below him, then pounced.
The two began to messingly make-out as Casey practically ripped off Donnie's gear and his own clothes, never in his life had he felt so horny.
He could hear the human half of him telling him to take it slow, Donnie wants it slow, he needs to calm down but... Damnit if the turtle didn't smell absolutely fucking amazing.
Casey pulled away from the kiss, he spread Donnie's legs wide, he stuck his fingers in Donnie's mouth.
"Suck."
Donnie turned bright red but he obeyed, he began to suck on two of Casey's finger, getting them all wet for him to be prepped.
Once Casey felt like his fingers were ready, he pulled them away and pushed them into Donnie's slit, causing the turtle to moan and whimper.
"Gah! C-Casey~! Fuck!"
Casey leaned closer to Donnie's neck, he let his fingers turn Donnie's insides into mush as he grazed his fangs against the turtles skin.
"Fuck, Casey! G-Go slow!" Donnie pleaded with a moan.
Casey obeyed... a little bit as he went a little bit slower but once he felt he was prepped enough he pulled out his fingers then moved away, he held onto Donnie's thighs and he positioned his cock.
"Now, Now" Casey teased, he rubbed Donnie's cheek, "I'll give you what you want, pet~ Just one.. Last thing.."
Donnie raised an eyebrow, he blushed darker at the new nickname, "And... What's that?"
"Submit to me."
Donnie looked at him in shock, "He.. He can't be serious"
"Oh I am serious, Doll" Casey leaned closer, using his arms to cage him as he started into his eyes, brushing the tip against his entrance, "Submit to me and I'll give you everything you want~"
Donnie bit his bottom lip once more, he thought about it but he really... really wanted Casey to fuck him.
"O-Okay, I... I'm submitting to you"
Casey grinned and slowly entered the turtle, teasing him in all the right spots.
"Ah, ah, ah~!!" Donnie cried out.
Casey bit his lip in pure bliss and joy, then leaned down and bit down on Donnie's shoulder... Hard.
"Ah~!!"
Donnie gasped as he turned limp as Casey continued thrusting... Hard.
"Fuck! Yes~ You feel so good, always so good to me~" Casey growled into his ears.
"Oh god, Casey!" Donnie moaned.
Casey kept thrusting now going at an inhumane speed with his new skills.
"Fffffuck~!! Yes! Yes!!" Donnie moaned, he felt his climax rising.
Casey growled and bit him once again, "Y-You gonna cum, doll~?"
"Y-Yes!"
Casey huffed as he hit Donnie's sweet spot that made him arch his shell, "Then fucking do it!"
Donnie cried out as he arched his back as he hit his climax but that didn't stop Casey as he looked up at him, who was grinning.
"Who says I'm done, Doll~? That was one... How many more can you do~?"
Donnie's mind went completely blank, he had no idea that the vampire DNA would turn his adorable, idiotic, boyfriend into a lustfull fuck machine.
But either way... He Loved it.
"Fuck. You're mine, Donnie~ I own you, your body is mine, your soul is mine, your heart is... Mine~" Casey chuckled darkly, as he continued thrusting into Donnie's body.
The Poor turtle couldn't even form words at this point, he just continued moaning like some sort of wind-up doll that goes on repeat.
His thighs were soaked, his plastron covered in cum, his face bright red and his neck and shoulders covered with bite marks and hickies.
"What's wrong~? Can't talk now" Casey grinned, his blue eyes staring down at the turtle, he rubbed his cheek,
"I.. Ah~!" Donnie tried to form a word but he couldn't, not with Casey practically driving him into a state of pleasure.
"God, your so fucking hot~ You wouldn't believe how badly I've wanted this for so long, just you and me... Locked way... My cock buried in your slit... Isn't that a nice thought~?"
Donnie moaned, it was a nice thought... a very nice thought, he loved this side of Casey but deep down, he missed the real Casey Jones.
And if you were wondering where the hell his brothers were. They were on an overnight patrol and wouldn't be back till the next day.
"Such perfect timing too~ Brothers gone, that bitch April gone~" Casey teased, licking Donnie's neck. He felt himself edging closer.
"Aww, I know you miss him, Doll~ But trust me, he'll be back~" Casey grinned, he bit Donnie's neck one last time as he gave his final thrust.
Cumming deep inside Donnie, to the point the turtle felt like he would explode.
"Ah~!!" Donnie cried out, he held onto Casey's shoulder as he wrapped his legs around his waist.
Casey held himself in that position, he groaned as he felt Donnie clamp down onto his cock.
"Heh, I knew you would like it, doll~"
Casey, still being a big softy helped Donnie clean themselves up, he then carried the turtle to his room, wrapped him up in a blanket and watched as the turtle doze off.
The next morning was a bit of shocker for Casey, he was nearly naked except for his boxers, his boyfriend covered in bite marks and hickies and barely being able to walk.
"Huh... Did I miss something?" Casey asked, he rubbed his head then shrugged as he cuddle next to Donnie who purred in response.
"Guess not, keep sleeping sweetheart~ Your man is right here"