A/N: Okay HUGE disclaimer here, one, I do not own these character, two, I have never written a fic with this particular kink before but hey dive in head first is what they all say, three I just wish there were more fics with McCoy gaining a bit, and lastly, there might be a sequel of sorts to this fic, stay tuned!
It starts with an offhand comment, but it causes an eye roll and an instantaneous snap that has Spock curious.
Jim thinks McCoy should take his own advice and eat a little more, and upon further inspection, Spock is inclined to agree.
McCoy thinks Jim is being ridiculous, that just because he's actually managed to lose a pound (or 7) since they set off as opposed to others (Jim), he in no way needs to change his meal plan.
Spock thinks Jim is right; McCoy is just far too skinny.
Logically, there is only one thing to do about this.
Saying Dr. McCoy was a stubborn man would be putting it lightly. Being on the receiving end of a brunt of the good doctor's emotionally fueled tirades, Spock knew that his plan couldn't exactly be enacted on a face to face confrontation.
No, if this was going to work, he was going to have to be a little more...stealthy; and he has just the thing.
It starts simple, with a few changes to McCoy's meal plan that he personally oversees.
He alters the standard low-fat creamer that McCoy uses in his coffee replacing it with whole creamer instead. Except he doesn't stop there.
No, next comes the subtle increase from two cubes of sugar to three included in coffee or tea.
And of course then there's the butter that gets added, rather liberally, to as many different dishes as feasibly possible.
But that's just the tip of the iceberg really. Just enough to get the ball rolling, because the thing is, McCoy is really, painfully skinny. It isn't until Spock endeavors to fix this that he realized just how thin.
He is suddenly acutely aware of just how lanky McCoy's frame is and how his uniforms, while one of the smaller sizes made, are still rather baggy.
McCoy really could stand to gain a few pounds. Really, Spock is just looking out for him, after all, it does come with the territory of his job.
Around the start of the second week of his plan, Spock ups McCoy's sugar intake by one cube. He also has the replicators stop dispensing light mayonnaise for him.
He also spends entirely too much time gazing at the Doctor's (still) flat abdomen through his tunics.
It's simply for tracking progress' sake is what he reasons. Logically he would need to keep an eye on the good doctor to see if his plan was working
Yes, logic, that's all.
Midway through week two, Spock decides to test a theory. He programs McCoy's meal card to increase proportions by 20%.
It's also the point when he has the card replicate a peach cobbler (made with Crisco over canola oil and white sugar, not brown) appear instead of McCoy's salad.
His lips twitch slightly when instead of a scowl, McCoy simply shrugs and treats himself to the unexpected surprise dessert.
Every third day Spock has the replicator dispense a new dessert.
From ice cream to pie, and even cakes and pudding, the desserts magically appear on McCoy's plate, and were he human, Spock thinks he might feel...delight, for watching McCoy lick the sugar from his fingertips.
He's been at it almost a month now, when he has the sugar increased to five cubes, and dessert to every two days.
It's also around that point, that he leaves a candy dish on McCoy's desk.
It isn't long before he sees McCoy with a red sucker in his mouth; Spock nearly smiles.
Spock realizes he's overlooked an error in his method of tracking progress when he walks into sickbay and is greeted by the sight of McCoy's rear.
He's been so focused on how that blue shirt still hangs a bit loosely on McCoy that he hadn't stopped to notice how the fabric of McCoy's pants seemed to stretch rather tightly over the definite swell of McCoy's rear.
But there's no denying it when McCoy is bent over a box doing inventory that he has started filling out. Just not where Spock had thought he would.
It's a start, and if anything, it just drives Spock all that much more that he's gotten a look at how well McCoy carries his weight.
When Spock first notices it, it's a complete accident.
McCoy is standing up straighter, very rarely, if ever, does Spock see the Doctor standing with the slight arch in his back that's commonplace for him. He also notices a disappearance of the nervous bounce McCoy is prone to do when thinking of a retort.
The pieces haven't quite set themselves in place when a bout of turbulence sends McCoy stumbling into Spock.
And while McCoy is apologizing, Spock can't quite bring himself to listen because he gets it now. It's so obvious.
McCoy has got a tummy.
It all makes sense now. The change in posture serves to hide the slight curve lurking beneath science blues. The lack of bouncing deters from the subtle jiggle of newfound flesh.
It started out with a simple idea to keep the Doctor healthy, but somewhere along the way, Spock found himself more concerned with the subtle changes he noted in McCoy's body and how the yielding flesh would feel beneath his fingers.
He can feel the tips of his ears burn as the pieces slide together.
He starts to keep a better eye on McCoy after he notices the slight bit of pudge forming around the doctor's middle. It's then that he starts to notice the other little changes as well.
How McCoy's cheeks appear fuller, his thighs a trifle closer together, and of course that ass. It's noticeably rounder as it presses against the unyielding fabric.
He thinks he might have a problem when he begins to take notice of how McCoy starts to tug at his shirt at an increasing rate when he stands. Then again he's got to have an attention to detail to track progress.
Yes, it's just being observant, nothing more.
When Spock gets his first touch, he earns a small gasp for his efforts.
It's only then that he realizes he's caressing through the fabric. He promptly pulls his hand away, but McCoy's eyebrows are already arching up incredibly high, and Spock knows he's been found out.
It's worth it, he thinks for the memory of fingers brushing along soft skin.
With the exception of Jim appearing for their bi-weekly chess games, Spock does not entertain many visitors.
So when there's a knock at his door, he isn't quite sure what to expect. He knows for a fact it isn't Jim, they're not scheduled to play for another two days.
It's with great surprise (read: raised eyebrows) that Spock opens the door and finds one doctor McCoy standing outside.
"We need to talk."
Spock has a fairly good idea why McCoy is here, but he lets McCoy control their conversation (for once), simply stepping back to motion him inside.
Once inside, McCoy goes abnormally quiet, his eyes fixed to a point on the ground as his fingers nervously tug at the hem of his shirt. The shirt that's pulling snuggly against his tummy, and Spock can't help but stare.
"I get it, I'm getting fat," McCoy says out of the blue, and Spock realizes, not for the first time there's an error in his plan.
"No, you misunderstand me, doctor, I do not mean to suggest the gain is bad, quite the reverse actually. I find myself...fascinated by it, if I'm to be honest."
And it's true, from the moment Spock noticed the way McCoy's pants were clinging to him, he's felt this need to map out the new flesh.
It's most illogical, but then again, where doctor McCoy is concerned, most things tend to err on the side of logic.
McCoy looks skeptical of this statement, and has his mouth open for a rebuttal, except all that comes out is a small squeak at the feel of insistent fingers dipping into the new roll and gently rubbing.
"I believe the weight suits you, doctor."
"Leonard, please, call me Leonard," he murmurs as he looks up at Spock, cheeks flushing slightly.
Spock nods, the corners of his mouth tilting up in a barely there smile, "yes, of course, Leonard."
He kneads the flesh below his fingers, categorizing every sound falling from Leonard's mouth with each new touch. It's quite tantalizing to know he's reduced that sharp tongue to breathy moans and desperate mewls.
He doesn't register he's kneeling at first, far too caught up in another task to even notice he's moved.
In fact, he's already undone Leonard's pants and pushed up the blue shirt, before he catches sight of the angry red indention, of pants a half size too small, staring back at him and realizes that he's moved to kneel.
He brings his hand up to trace the marks, fingers circling the imprint left by a button pressed firmly against pale flesh, before he leans in to nuzzle against soft skin.
He can feel Leonard shiver above him, as he lets his fingers wander. Hear the slight hitch in breathing with every stray lick or nip, pinch or caress left in his wake. He noses at Leonard's hip, tongue tracing the burgeoning love handle he finds where pointy bone once stood.
Leonard comes with a ragged moan as Spock digs his fingers into fleshier hips, tongue tracing the fading imprints along the Doctor's waistline.
And isn't that all just fascinating?
It's later when the ruined boxers have been disposed of and they're lying in Spock's too small bed that Leonard finds his voice again.
"You really like this," he asks, voice barely above a whisper as he turns a curious gaze to Spock.
In response, Spock moves his hand to rest, flat palmed against Leonard's abdomen.
"I find myself…illogically drawn to this," he says carefully, thumb brushing below Leonard's bellybutton.
Spock isn't sure which he appreciates more, the faint blush coloring Leonard's cheeks, or the small smile that finds its way to his lips at the answer.
He decides, finally, that he appreciates the chaste kiss Leonard places to the corner of his mouth the most.