Jim drags it into their quarters three days before Christmas. It looks, at first glance, like a Christmas tree. But when McCoy looks a little closer, he can see that it's not. The fact that it has gently waving tendrils all over it is a big clue. The colour, too, is off-putting—it's a glossy, unnatural-looking green, which McCoy finds more unnerving than if it were orange or purple.
"What the hell is that?" McCoy asks. He eyes it nervously.
"It's a Christmas tree!" Jim replies gleefully. "Sulu got it for us. It's exactly like a pine tree in every single way."
"Jim, it's got tentacles."
"Those are just really big pine needles."
"Get it out, now."
"Bear with me, Bones. Sulu says it's not harmful at all, and he's got one just like it in his quarters. It's going to grow flowers that look exactly like Christmas decorations so we don't even have to do anything with it. Look, you can see the buds already."
McCoy leans in slightly, being sure to not get too close just in case Sulu's wrong. "So I can. Now, what's it doing in here?"
"You need some Christmas spirit." Jim nuzzles his ear, tugging at the bottom of McCoy's uniform shirt. "Let me put some Christmas spirit inside you, Bones."
"Yeah, sure, and while you're doing that, the alien tree will start to eat us, and that's really not how I want to die. And I especially don't want to be found after dying that way, Jim."
"What if I fuck you over the arm of the couch so you can keep an eye on it?" Jim asks, nipping at his jaw. He's using his "considerate" voice, so he clearly thinks this offer is some sort of favour or compromise.
Still, the tree doesn't do anything too suspicious when Jim does fuck him over the arm of the couch, so Bones supposes it can stay.
The first flowers bloom on Christmas Eve and McCoy has to admit they're beautiful, even if he does still find the tree creepy. They flicker and glow from the inside out, as if they've got candles inside them. He tries not to look at them too much, in case they're some kind of hypnotic lure.
They've both slept badly for the past few nights—waking up exhausted from particularly lurid dreams—so McCoy doses himself with a mild sedative before they go to bed. Jim refuses the hypospray.
"I'd rather have natural, disturbed sleep than unnatural sleep and an allergic reaction," he says.
"Stop holding that against me," McCoy grumbles. He gets under the covers, pulling them over himself firmly in the hope that Jim won't steal them later. "It was a high-stress situation and it hasn't happened since."
"I think you're saving it up." Jim grins and kisses him, slipping his fingers between McCoy's and squeezing lightly.
McCoy glances across at the doorway to the living room in their quarters. It's lit by the faint, eerie glow from the tree, so he looks back at Jim quickly. "That's for me to know, isn't it?" he replies, and then he kisses Jim meaningfully.
The sedative's already at work when they have sex, and McCoy drifts off to sleep almost before he's come. It's not surprising when he dreams about sex, then, though it's very different to the slow, lazy, half-asleep sex he had with Jim.
His legs are spread wide apart; so wide it aches in a way that feel amazingly good. One leg is slung over one of Jim's shoulders and Jim's hand is pressed to his other thigh, holding him open and in place as he thrusts into McCoy again and again. The fingers of his free hand play over McCoy's cock and balls, then dip down to tease the place where Jim's dick is sliding back and forth, nudging inside just enough to make McCoy pant and beg.
"Jim, god, please," he moans, because it feels so good, so real. Almost too real, it occurs to him. He forces his eyes open, waking himself. Jim's really fucking him, but McCoy can see in his half-open eyes that he's still asleep.
A look across the room confirms his suspicions. Tentacles and flowers line the doorway, stretched across from the main body of the tree. Most of the flowers are fully open now, instead of the closed spheres of the daytime, and a steady trickle of silvery-white pollen is streaming out of them.
"Goddammit," McCoy says. "Jim, ahh—wake up."
Jim doesn't wake up, of course. Whatever the tree thing's up to, it still has him firmly under its spell. He tries pinching Jim's earlobe to rouse him, biting his lip hard when Jim's only response is to curl his fingers around McCoy's cock and squeeze.
McCoy gropes for the sedative hypospray on the nightstand and presses it to the side of Jim's neck, because it's the only thing he can think of that's in his system that definitely isn't in Jim's. The worst that can happen is nothing at all, but the pollen seems to be suppressing orgasm and McCoy's muscles are starting to complain about the position Jim's holding him in.
Luckily, the sedative seems to disturb the pollen's effects after less than a minute and Jim's eyes clear and focus as he wakes up. "Bones—wha...?" he mumbles, his movements stopping abruptly.
"It's your harmless goddamn tree, Jim," McCoy growls. "It's drugging us. Look at the door."
The tree, now that they're both awake, has started retreating rapidly back to its pot in the living room, but its flowers aren't closing as fast. They leave a trail of the pollen across the floor, which disappears almost as soon as its been laid.
"Son of a bitch," Jim exclaims, watching it go. He rubs McCoy's thigh soothingly and pulls out, grabbing his pyjama pants from the floor. "C'mon, let's airlock it. I'm the captain," he adds when McCoy opens his mouth to object. "I get a few free passes. If I don't use them before the five years are up, they're gone forever."
"Fine. But you're carrying it, because I'm too sore and that's your fault." He pastes on a frown, but secretly, McCoy quite likes throwing things out of the airlock. He dresses in slightly more clothes than Jim, and then, picking up the hypospray in case of emergencies, follows him out of their quarters and down to the nearest airlock. It takes them a while; the sedative might have woken them up but neither one of them has come yet, thanks to the pollen, and they're both sporting obvious erections.
Shutting the tree inside the airlock, opening the hatch to space and watching it get sucked out is one of the best Christmas presents McCoy thinks he's ever had—closely followed by the blowjob Jim gives him right there against the wall.
"This is the best Christmas ever," he says into Jim's ear as he jerks him off in return.
"Mmmngh," Jim says in apparent agreement, and comes across his palm.
They're standing close together, recovering, when something occurs to McCoy. "Who else has one of those trees?" he asks.
"Just Sulu, I think," Jim replies, stroking his fingers through McCoy's hair. "Why?"
"Doesn't he share his quarters with Chekov?"
"Well, yeah, they requested to move in together a while—oh, fuck. We should probably go and do something about that, right?"
McCoy sighs heavily. "This is the worst Christmas ever."
"You're going to have to make up your mind," Jim tells him, then claps him on the back. "Once more unto the breach."
It says a lot about life on the Enterprise, McCoy thinks, that sedating and then pulling two very naked members of Jim's bridge crew off (and out of) each other isn't the most embarrassing thing he's had to do since joining Starfleet. It's probably about fourth on the list.
Sulu apologises profusely, of course. "I really had no idea," he says as they airlock the second tree. "If I'd known, obviously I wouldn't have given you one. I'm really, really sorry. There aren't any more on the ship."
"Go back to bed and don't worry about it," Jim says. He pats Sulu's shoulder a little awkwardly. "Try to get some real sleep this time."
"And come see me tomorrow if you have any lingering problems," McCoy adds.
"Yes, doctor," they both say. Chekov reaches for Sulu's hand as they head back off to their room.
"They are adorable, Bones." He gestures to McCoy and they start walking in the opposite direction, towards their quarters.
"I don't know how you can say that after seeing what we saw."
"Adorable," Jim insists, holding onto McCoy's hand. "Were we ever like that?"
"I'm not as flexible as Chekov."
Jim laughs suddenly. "No, jesus. I didn't think anyone with normal joints was that flexible." He stifles a yawn, leaning closer to McCoy so their shoulders bump gently together. "Talk about an eventful Christmas Eve," he says.
"No more Christmas trees that aren't really Christmas trees?" McCoy asks. He types the access code to let them into their quarters when they get to the door. Jim curls around him immediately upon getting into bed, kissing McCoy's neck.
"None at all. 'Night, Bones."
"'Night," he replies, and falls asleep thinking of how boring his life would be without Jim Kirk.