So, this is my newest story. Hope you enjoy!

Title: Vaccine Side Effects

Summary: slash/lemonIt was time for the yearly human vaccine shot that was given out to everyone(that was human) in space, and Pavel was a bit nervous. But with aid from the after effects of the vaccine and both Jim and Bones there, he's bound to get over his fit of stomach butterflies. [Bones/Pavel/Kirk]

Warning: First ever threesome lemon posted. Iv'e been playing with them recently.

Dedication: Ah! This time I had an AMAZING Beta help me. Lovely Miss Fortunate, as you all know her. This is for her, my inspiration and my greatest help with this!

Captain James Kirk was an honorable man. Really, he was. Maybe he was silly at times. And maybe he was too relaxed with his crew, but who wouldn't be with such an amazing crew?

That was his story and he was sticking to it.

He sat now in his "overlord" chair, as he had come to call it. His arms were crossed and he leaned back, crossing his legs in the only possible way a guy could cross his legs without hurting—ahem. Yes. The room was a bit chilly, but he was fine with this temperature.

"Captain!" the Russian ensign called out as he swiveled around in his chair to face Jim. "Captain, I'm in love with you!"

Okay, that was a lie. Pavel Chekov did not turn around and confess his love. Jim could surely wish, but he knew it wouldn't happen. Not like that, anyway.

"Captain," and that was Bones here to confess his love, "Captain, stop imagining other people confessing their love to you."

Jim winced as he turned his chair to face McCoy. "Damn," he muttered. "How'd you know what I was doing?" he asked, curious.

"It has something to do with the way I've known you for so long. It's very frightening to imagine, I must say, but I'm still clinically sane, so I shouldn't complain," Bones responded easily.

"So, what brings you to my evil lair?" Jim asked cheerfully.

Bones opened his mouth to ask about the remark on an 'evil lair,' but decided against it, instead handing the captain a clipboard. "It's that time of year," he announced. "All humans need to get the shot."

Jim let his eyes roam over the paper he held and read what little he could understand that wasn't doctor mumbo. But reading it didn't matter, he knew exactly what the paper meant and what Bones was trying to tell him. "Damn," he cursed for the second time.

"Yeah, so I've drawn out a plan that will bring in the ones who work night shifts first. Then we'll move onto the smaller positions and go up from there." Bones took back the clipboard and flipped the page over. "We'll build our way up. As Captain—"

"I know, I have to be there for each one. I remember," Jim grumbled. "When are you starting?"

"Now."

Jim groaned as he stood up from his comfortable chair, glaring at Bones. "Fine, Spock, take over for me, will ya'?" he asked. He didn't really have to ask, could have just commanded, but he didn't want to come off as clamorous or demanding.

"Yes'sir," Spock replied in his monotonous voice as he sat in Jim's previously occupied seat. Jim looked at his seat longingly before turning to leave. Not, of course, without taking one last look at the Russian ensign with an appreciative look.

Pavel watched the doctor and the captain leave, letting his eyes trailed over the two lean bodies. He could dream, couldn't he? Both were dashing in looks and each had his own quirkiness, something Pavel immensely enjoyed. He swiveled back to his original position and tapped at several keys and made sure that the Enterprise wouldn't crash into anything anytime soon. It was his job.

"What do you think they're talking about?" Sulu asked him. Actually, he was addressing the whole group of people on the bridge, but Pavel liked to pretend that Sulu talked to him alone.

Pavel shrugged his shoulders as he leaned back in his chair. "I do not know," he replied, accent making his answer choppy.

"They're talking about the shots humans have to get every year while working in space. It is mandatory for a human's survival." The way Spock had explained it seemed like it was read right from an encyclopedia, similar to what Pavel had once sounded like.

"What shot?" Sulu asked.

"The name slips my mind, but it is to make sure that humans stay healthy, despite eating all the food they call healthy."

Pavel nodded. He had read about this somewhere, but it seemed to slip his mind, also. He had also read about the side effects one could get from the shots. He remembered that each person had different side effects, but he couldn't remember the different ones. Doctor McCoy probably knew, so it didn't matter whether he knew or not.

"Because they said they're starting bottom first, there's a chance we won't have to get the shot until tomorrow, if we're lucky," Sulu calculated. "We are the top, so I don't see why not."

Pavel mulled over this for a few seconds. He wondered if he would have to go into the sickbay alone with Doctor McCoy and Captain Kirk. He let his mind wander to all the things he could get away in there with just the two of them. The thoughts were not unwanted. No, rather, he embraced the thoughts in moments when he knew he had no chance with either, let alone together.

Stopping himself from going too far into his thoughts of him bent over a recovery bed while his captain did things almost unimaginable to him as the doctor watched, Pavel sat up and looked surprised when he was interrupted by a hand waving over his face.

"Are you okay, Chekov?" Sulu asked the younger boy. The Russian ensign slowly nodded his head, then smiled. He was doing more than okay, he thought to himself. He got to see McCoy and Kirk later, together.

The rest of the day passed in a lazy manner, nothing remarkable to take note of. Of course, eventually, the crew on the Enterprise started to disappear one by one, leaving Pavel slightly confused, but when he inquired about it later, Spock had replied by explaining that the shot they were getting usually put them in odd conditions that some simply stayed in bed. Of course, as Spock mentioned this, Pavel noticed that the Vulcan was grumbling odd curses in a foreign language.

Soon, the nightshift-ers began to file in despite that it was still early. According to Spock, the ones on nightshift had received the shot first, allowing them time to recover to tend to the Enterprise.

When the last human left the bridge to get the shot, Pavel began to wonder when his name would be called. Would he be the last one? He wasn't sure if he should feel honored or belittled. Maybe a bit of both. At the moment, Pavel was simply confused.

Just as his shift began to end, Spock called out to him.

"Chekov, they request your presence down at the sickbay. Go quickly."

Pavel nodded as he left the bridge swiftly and headed down to the appointed place. His blood rushed in his veins and he could hear his heartbeat as clear as a drum beat in an empty room. If he was the last one, then that would mean there was a chance that he would be alone with Doctor McCoy and Captain Kirk, and the thought made him excited and nervous all in one turning.

"It'll be okay," he muttered to himself in Russian. "I'm just overreacting. Nothing is going to happen." Pavel stopped a ways off from the entrance to the sickbay and took in a deep breath. He would be okay. Stepping forward, the doors automatically opened up for him and he delved inside.

Previously in the sickbay.

"What the Hell do you think you're doing, Jim?" Bones asked the cocky captain.

"Getting what I deserve," Jim replied in his "better-than-thou" voice he often used to annoy the doctor.

"And you think you deserve Chekov?"

"You're just jealous."

"I'm not Jealous, Jim."

"Don't worry, I'll let you have some fun with him, too."

"Really?" Bones asked, then stopped. "No! That's not what this is about! I'm talking about the kid. By the way, he's a kid. I'm sure he's not even legal."

Jim gave Bones a stare and smiled. "You tell me," he replied. "You're the one that was drooling over his file, just now. Though, I have to admit, that is an adorable picture."

"Isn't it? No! Stop distracting me! What do you plan on doing to the boy when he gets in here?" Bones asked, a worried look on his face.

Jim smirked as he stepped closer to Bones and put a hand to the doctor's chest. Leaning up to put his face just a hair's breadth away from the other, he spoke, "I'm going to first make sure you give him the shot. Then, when he starts to get slightly delirious, I'm going to help him." He slid his hand down Bones' chest and moved it to the small of the other's back. "Then I'll hold him for a little while. Like this." Leaning his face even closer to Bones', he spoke again. "Then I'll kiss him, like this."

And Jim brushed his lips lightly over the doctor's, then, with a smirk, he closed his eyes as he deepened the kiss, even going as far as to use his tongue along Bones' lips, happy at the way the other parted them.

Pulling back, he smiled. They had done this before, but today would be different, they could both feel. "And that's my plan," the captain declared.

"I like your plan."

"I knew you would."

Pavel stepped into the sickbay and paused. Both Captain Kirk and Doctor McCoy were standing quite close together with wide grins on their faces. Pavel wondered if he had walked into a personal moment, but knew he was wrong when the Captain turned to him, grin still in place.

"Chekov! You're the last one to get the shot! Come in!"

Pavel took a wary step forward, but hesitated. "Keptin, you seem happy," the ensign pointed out.

"It's because I'm in an awfully good mood, Chekov, don't worry." But the way he said it made Pavel even more nervous than before. Fidgeting, he walked over to where Doctor McCoy stood.

"The shot?" he asked.

McCoy nodded and motioned for Pavel to sit on the bed. Pulling out a hypospray, he smiled. "This will sting, but don't worry, the pain isn't bad. Also, you may feel some side effects; I advise that you stay for a few minutes afterward so you have time to get over them."

Pavel nodded his head, unsure as to how he should answer. Stepping over to the bed, he hopped up to sit on top. A fleeting second later, he felt the bed shift slightly and looked to see the captain jump on the bed beside him from the other side.

"I'm so glad I only have to do this once a year," Kirk muttered, leaning back on his arms as he looked up to the ceiling. "It was so boring today!"

McCoy prepared the hypospray and moved Pavel's shirt's collar out of the way, startling the younger boy at the first touch. "Relax," the doctor muttered. He stabbed the hypospray into the juncture where the neck met shoulder. "And that should be it," he announced.

Pavel heaved a sigh of relief as his shoulders sagged. "And the side effects?" he asked. But already, he felt his skin heat up and something odd happen to his body. It was as if he was—

"Oh, shit," McCoy whispered.

"What's wrong?" Kirk asked quickly, worried.

"He just had to have this side effect," the doctor grumbled.

"What side effect?" the captain asked. "Chekov, what's wrong?"

And with a strong blush, the Russian replied truthfully. "I'm aroused."

And Jim's world just got brighter. The boy was aroused. As a side effect. He could use this.

"Are you feeling anything else?" he asked, truly concerned as he placed a hand on the small of the boy's back.

Chekov shivered at the touch and moaned. "N-no," he stumbled. Jim smirked and leaned in closer.

"Are you sure there's nothing we can do for you?" he asked. "Because we can do anything you like, just say the word."

The captain was whispering directly into his ear and Pavel moaned again, leaning into the warmth that Kirk emitted. He couldn't just tell them he wanted to be fucked by either of them. Well, he could.

"I want you both to fuck me," he growled out in Russian. Surely they wouldn't—

"Don't mind if I do," McCoy answered as he stepped forward, capturing the Russian in a kiss.

Pavel was caught in surprise as the doctor kissed him. It took him a moment to realize that he could indeed respond to the kiss. He leaned forward and deepened the kiss by opening his mouth and closing his eyes.

The kiss was heated and perfect, just as he imagined it to be, but he was suddenly pulled away. He blinked his eyes open and looked to see why he had been pulled away, but was stopped when he felt another set of lips on his. Distinctly, he made out the features of one captain, but he paid no more mind as his body caved in to enjoy the kiss. It was an opened mouthed kiss, bold and haughty, just like the captain himself.

"Jim, slow down, you'll give him an aneurysm," the doctor warned.

Captain Kirk pulled back and turned to McCoy. "But Bones, this is so fun! Do you know how long I've been waiting to do this?" he asked.

Pavel was shocked at the confession, miffed at why the captain would want him so long. "Keptin," Pavel started, but was stopped by a set of lips on his. McCoy's, this time.

"Call us by our names," the doctor advised. "Bones and Jim. Because with what we're about to do, you don't have to worry about calling us Captain and Doctor."

"Unless you're into some kinky shit," Kirk growled out with a grin. "We can try some of that later." Jim leaned down to Pavel's neck and started to nip and lick, leaving marks.

"Jim," Pavel started, testing the name out on his lips. "How long...?" he didn't finish his question, leaving it in the air.

But the captain knew what he wanted to ask. "For as long as you've been serving under Spock," he stated. "So it's been, what, five months now?" He returned to his nipping and marking, greatly enjoying the taste of the Russian.

"It's been about the same for me," Bones replied sheepishly. Shrugging, he leaned forward to kiss Pavel again. "Now, Chekov—"

"Call me Pavel," he replied with a grin of his own. He let out a small gasp when Jim bit down on a particular spot.

"Mm, Pavel, then," Bones responded. Instead of speaking, he picked (impatiently) at the bottom of the younger's yellow shirt. "This needs to come off. Now."

Pavel had no say in what happened to his shirt as he watched it fly off into the distance. Jim had moved up the neck and bit his ear playfully. "And the pants," the captain whined. "I want those off of you now."

The young ensign watched in awe as he was stripped of his pants, and shoes and even his socks, leaving him clad in his underwear. He felt unprotected and vulnerable. It was clear as day where his underwear tented up at the obvious arousal.

"I don't want to be the only one naked," he whined in Russian, hoping Bones would understand this bit also.

"Jim, strip," Bones demanded, leaving no room in his voice for argument. Not that Jim might have wanted to argue.

Jim pulled back and slowly took his shirt off in a tantalizing manner, making both Bones and Pavel fill with frustration. "Jim," Bones growled in warning. When the shirt was fully off, Jim scoffed at the doctor.

"And why do you still have a shirt on?" he asked. Bones nodded and stripped his shirt off as well, leaving all three men shirtless. "Now we move onto you," Jim announced as he jumped off of the bed and onto the floor in front of Pavel. He moved forward to capture the boy in another kiss, but didn't stay to continue as he moved down the boy's chest.

Pavel saw as Jim moved down that Bones moved behind Jim and raked his hands down the captain's back until they came to the pants. "Pants off," Bones growled as he slipped his arms around and moved to the front to undo the clasps and slide them off. Pavel felt Jim's lips shiver against his chest, making him shiver in turn.

When the pants came off, the underwear was pulled off with it, making Jim the most naked of the group. Chekov moaned at the sight and raked his fingers through his captain's hair. He tightened his grip on the hair and pulled the captain up to kiss him.

"I feel lonely," Bones muttered with a frown. He leaned forward and wrapped his arms around Jim's naked torso, pushing his own clothed erection against Jim's bare behind. Leaning over Jim's shoulder, Bones looked to Pavel. "Can I get a kiss?" he asked, a scowl adorning his face.

Pavel nodded with a cute smile on his face as he did what the doctor asked. The kiss was open mouthed and full of tongue action, leaving Pavel wanting more. As he continued to kiss Bones, Pavel felt Jim slip down and rest between his knees, and what came next wasn't as surprising as he thought it would be.

His underwear was ripped off as Jim admired him for a moment. He leaned forward, giving a testing lick and Pavel cried out into Bones' mouth in pleasure. "More," he managed to mutter against the doctor's lips.

Jim decided that he did like the way Pavel tasted and continued by wrapping his mouth around the head and giving a long suck. Pavel cried out again, tightening his hands in Jim's hair. Bones smiled into the kiss and pulled back. Pavel couldn't deal with both at this moment. He stepped away and walked over to a cart and sniffed around, looking for something.

He smiled when he heard Pavel shout. From the sound of it, it seemed that Jim had just taken him all in his mouth. He often had the same reaction when Jim would do that to him. He glanced over at the pair and moaned under his breath at the sight. Pavel was sitting with Jim on his knees in between the boy, sucking him off like he knew Pavel would want.

Turning back to his task, he moved things around until he finally found what he was looking for. Holding the tube up in triumph, he walked back over to the pair. "Who should I start on first?" he asked them. "Pavel or Jim?"

Pavel was confused as to what Bones' was asking, but didn't pay any mind, his whole being preoccupied on the task at hand. The blow job, that is.

"Pavel," Jim said around Pavel. "Prepare him first."

Bones nodded and moved to the other side of the bed. "You'll have to release him, first," Bones informed. Kirk pulled away from Pavel with a 'pop' sound and moved up to kiss Pavel, who whined at the loss.

"On your knees," he growled in a husky voice. Pavel nodded as he moved to do as he was told. He got on his hands and knees so that he was on the bed correctly. Bones smiled and opened the tube to squeeze whatever it was onto his fingers. "What is that?" Jim asked the doctor.

"Healing ointment," Bones replied with a grin. Lathering his fingers, he moved them to Pavel's ass and fingered the hole with just the tip of his pointer finger. "You ready?" he asked the ensign, but didn't wait for an answer as he shoved the finger in swiftly.

Pavel cried out in pain, but he knew there was more to it. After he adjusted, he pushed back on Bones' finger. "More," he whispered.

Bones smiled and did as he was told, adding another finger. He moved them around inside and scissored them to stretch the boy. "How do you feel?" he asked the boy.

"Full," the boy replied. Jim grinned as he moved directly beside the ensign.

"It'll get better," he promised as he leaned down to kiss the boy. Pavel hummed in joy as he wiggled his hips, pushing back on Bones' fingers.

"More," he said against Jim's lips.

"Needy little whore, aren't you?" Jim asked as he kissed him again. Bones followed Pavel's word and added the third finger. He moved them around and stretched the boy to his fullest.

"Your turn," Bones announced when he pulled his fingers out. Pavel whimpered at the loss of something inside of him, but stopped when he noticed Jim moving.

Jim lifted Pavel up so he could slide under the boy. "This'll be more comfortable," he explained. Moving, he adjusted himself so that his cock was set at Pavel's entrance. Pavel seemed to know what to do and slowly sat on the captain. The two both moaned loudly, making Bones' smile.

The doctor slicked his fingers again and moved to Jim's own entrance. Just as the ensign fully engulfed the captain, he pushed the first finger in. He made quick work this time, knowing just the right ways to prepare the captain. In several moments, the task was complete and Bones pulled his fingers out. He shifted the other two so that he could climb up on the bed, his legs tucked underneath Jim's thighs. "I wonder if this table will hold three fully grown men," he wondered curiously.

"Bones, stop talking and just—Oh shit!" Jim cried out as the doctor entered him in one swift movement. They were all still until Bones started to move, in turn moving Jim who was lodged inside of Pavel.

As they continued to fuck, Pavel cried out when he felt Jim hit something inside of him. Jim knew what that reaction was and aimed to continue to hit that spot. Bones shifted slightly so that he hit Jim's own prostrate, eliciting a cry from both Pavel and Jim.

Bones moved forward to bite down on the Russian boy's shoulder, leaving a bite mark on the spot. "Faster," Pavel moaned and Bones picked up the speed, moving faster as he was asked.

Jim felt the way his balls constricted before he gave a final cry and came in Pavel. The other two came at the same time, as an after effect of Jim's own orgasm. Bones continued to pump in and out of Jim for a few more times before stopping to pull out.

The moment was silent as the three paused to regain their breath and return to the present.

"Do you think we can all fit in the Captain's Chair?" Jim asked.

Hope you liked it! Leave a review to feed my small ego!