Rodney never understood why people fetishize military paraphernalia until he meets Samantha Carter and spends a lot of time looking at her tits. They're great, fantastic even -- way more interesting than the unsubstantiated "science" coming out of her mouth -- so he's looking, appreciating, fantasizing, and her dog tags, which are right there, get swept along for the ride. She wears them over her shirts, and there's just something truly sublime about the way they hang off that ridge of rippled fabric where her t-shirts stretch across her breasts.
Then he gets sent to Siberia, where it's cold and Russian, and not even the thought of Samantha Carter's tits can keep him warm at night. Well, sometimes it works, but mostly the shine's worn off, and even he can't make himself believe that she'd fly all the way to Siberia to climb on top of him and tell him she was wrong to dismiss his warnings which were based on actual science just because she didn't like what it meant for Teal'c. That's when things fall apart and he starts thinking about how he was wrong and has to take his hand out of his pants so he can pull the covers over his head and suffocate himself, or whatever, fall asleep, whichever comes first.
Eventually, he and Sam kiss and make up; he goes back to fantasizing about her tits; then there's Antarctica; Atlantis; John Sheppard.
Sheppard gets bitten by this bug, this horrible blue bug, and Rodney would have bent space-time to save him, but instead they have to kill him, slit open his shirt and shock him dead, and it's terrible, horrible, but afterwards, after Sheppard's back on his feet and leaning against things with his hips cocked and that flirty grin on his face, Rodney thinks about how Sheppard wears his dog tags under his shirts where no one can see them.
After that, Rodney starts looking for the faint outline of the chain, the bump of the tags. Sometimes Sheppard will be bent over, digging through his pack or retying his boot, and Rodney will stare at the back of his neck where the chain's slid out from the collar of his shirt. From there it's a short hop to sneaking peeks of Sheppard's chest in the locker room, the showers. Sheppard is hairy, and has a farmer tan, and sometimes doesn't wear socks with his crosstrainers.
Rodney's never gotten the hang of being subtle and Sheppard crowds him into an empty doorway one afternoon after a mission and makes a pass at him. Next they're fucking in Sheppard's room. They do it a lot after that. Rodney likes it best on his back, face to face, so that he can feel Sheppard's dog tags drag over his chest while Sheppard fucks him. It's kind of hypnotizing to watch them swing back and forth with Sheppard's thrusts, and it becomes normal to hear them as they clink together or slide across John's chest, or slip between them as they lie on their sides and kiss, afterwards.
Sometimes when Rodney's kissing his way across John's chest, the chain will get in the way and Rodney will suck it into his mouth, lick its row of little balls along the top of John's nipple. John likes that too.
Life goes on. Elizabeth calls a meeting. Rodney brings his lunch and his laptop and someone's rearranged the modular table so that it's long and skinny and John sits across from him and they play footsie, but in a vigorous, manly way that might be mistaken for a kick fight if anyone were to look under the table.
Elizabeth's talking, something like, "The IOA, in their infinite wisdom, has decided that rather than addressing our concerns about the vulnerability of the supply chain or our relative lack of air support, our needs would best be served by this trivial and irrelevant policy change." She uses different words, but the IOA's mission statement (To Delay and Obstruct!) comes through loud and clear.
"Excellent," Rodney says, "another win for bureaucracy. Can we go?"
Elizabeth's administrative assistant gives him a box and an envelope; next to him, Carson also gets a box and an envelope. John doesn't get either.
"It might help if you were to wear yours while you present the idea to the science team, Rodney," Elizabeth says. "To show your support."
Is it spirit week? He definitely missed something. He trots out of the conference room, juggling his lunch tray, laptop, envelope, and box. John slides up next to him and Rodney hands him everything but the laptop.
"What was that all about?" Rodney asks. "Are we having a fashion show?"
"You are," John says, opening the envelope with his thumb. "IOA says civilians have to wear tags now."
"So they can more easily identify our charred and withered bodies. That should save on paperwork. Also, a fantastic show of confidence on their part," Rodney says, barreling down the hallway to his lab. He had at least three brilliant ideas during the meeting and wants to get to work on them immediately.
John catches him, drops something over his head, risks a kiss to his ear. "Yours say you're allergic to citrus."
Rodney's on autopilot. He bats John away and rushes for the lab. Brilliant ideas wait for no man, not Rodney McKay, certainly not John Sheppard. He's rushing and jingling and John put dog tags on him and suddenly he's so hard he can barely walk.
He ducks into an empty lab, grabs himself through his pants with one hand and reads the tags with the other. The first two are identical, stamped with his name, social insurance number, and blood type. A third, smaller tag has a medic alert symbol on one side and a list of his allergies on the other.
He calls John on a private channel. "You need to come have sex with me right away."
"Can't," John says. "Busy."
"You don't understand," Rodney says. "These tags make noise and I was supposed to be solving the energy crisis but now all I can think about is you fucking me."
"I can see how that might be a problem, Dr. McKay."
"Oh, fuck," Rodney says, sliding down the wall. He puts his laptop aside and gets his pants open. "You're in a meeting or something, aren't you?"
"That's right," John says lightly.
"Can't you get out of it? This is important!" Rodney pulls his dick out and gives it a squeeze. "You don't have to fuck me. How about a blowjob? You give the best blowjobs. God, your mouth --"
"I'll have to get back to you on that."
"Tell them it's an emergency. Tell them --" He gives up on John, wraps a fist around his cock and just goes for it.
"McKay, are you...?"
"Yes," Rodney says, "I am. I'm jerking off -- in an empty lab -- oh, god -- because I can't hear dog tags and not think of you, and now I'm wearing them and I'll, oh, I'll never, I'll never --" He grabs his tags with his free hand and they clink together just like they do when John's stroking into him and he comes all over his fingers and the floor and the knee of his pants and also the wall.
John swallows so loudly Rodney can hear it over the roaring in his ears.
"Mmm," Rodney says, mellow. "That was pretty hot."
"I'd have to agree, Dr. McKay. I'll be with you as soon as I'm through speaking with Colonel Caldwell."
"Oh, and you let me --"
"You said it was important," John says, and Rodney knows he must be smiling.
John signs off. Rodney fixes his pants, grabs his laptop and gets up. Just before he leaves the room, he drops his dog tags down the neck of his shirt and shivers as they hit his skin.