This is Stargate Atlantis (SGA) fiction, exploring the relationship between Rodney (McKay) and John (Sheppard).
We posit that Rodney's much-publicised attempts to impress Dr. Samantha Carter are in fact simply a bit of bearding to throw people off the scent.
Rodney's suppressed first name is Meredith. He has a physicist sister Jeannie, had a dog that ran away when he was a kid, and kept a cat in his appartment on Earth before going to Atlantis.
Meredith is an anglicisation of Meredydd which means "protector of the sea" (perhaps quite suitable for a protector of Atlantis). It can be given to males and females. [Alternatively: Meredith - from the ancient Welsh personal name Maredudd (pronounced with emphasis on the middle syllable); udd "lord".]
Before joining the Atlantis project, Sheppard was based at the McMurdo Station on Ross Island in Antarctica. We all know what goes on at Antarctic base stations — Sheppard is likely to have at least known about people being in temporary and unconventional relationships due to location.
There's an interesting article here where it says about Scott's hut being across the bay from McMurdo. That can be a useful spur for reflection about life, meaning, etc. It also reveals the concept of being "married on the ice", which is the name for having a temporary relationship — irrespective of any relationship which you might have with someone on another continent, which is in temporary abeyance.
There's also a nice article here which contains the pretty paragraph:
The ice is absolute. It washes us away. In the bare de-ozonized sunlight the notion of right or wrong and what matters in the world is a feeble candle glow. All we have left is the self we brought encased in our bodies, our professions, the reflection of ourselves cast by our acquaintances in the world. The ice breaks our hearts, and in doing so, shows us that what we really are has little resemblance to the self image we harbor in our minds.
Another excellent quote: "For scientific leadership, give me Scott; for swift and efficient travel, Amundsen; but when you are in a hopeless situation, when there seems to be no way out, get on your knees and pray for Shackleton." — Sir Raymond Priestley. We can definitely adapt that by substituting Rodney for Scott, Weir for Amundsen, and John for Shackleton. However I'm also more than inclined to allow Rodney to praise John with the deathless words "A good man in a tight hole."
"Superhuman effort isn't worth a damn unless it achieves results." — Ernest Shackleton.
"Many times I have thanked God for a bite of raw dog." — Robert Peary (1856—1920), polar explorer. Let's have John know this quote, let it illuminate his actions in whatever crux we place them.
Housman's description of his feelings for Moses Jackson: 'An unremitting, lopsided, lifelong, hopeless constancy'. Make Rodney a reader of Housman.
Ask me no more, for fear I should reply;
He would not stay for me; and who can wonder?
Night holds Hippolytus the pure of stain,
In fact, thinking about it, Rodney is Housman! Their opinions of their peers are similar (Housman's preface to his fifth volumn of Manilius — M. Manilii Astronomicon — describes Robinson Ellis, a former professor of Latin at Oxford, as someone whose readers were "in perpetual contact with the intellect of an idiot child").
Now, who might be familiar with both textual criticism and Rodney? Daniel Jackson perhaps? And how can we introduce a first bit of AEH to Rodney? What if he has to do a funeral speech? Let him read Parta Quies. What if someone — Zelenka maybe? — dies? We could have Zelenka and Rodney on an away mission, Z. dies in Rodney's arms, but just before he goes, confides something shocking to Rodney: "If you ever see Ford again, tell him... tell him I loved him." The realisation that Z/F's situation and his and John's are parallel, works together with Housman's beautiful poetry, to break the logjam that had been holding him frozen for so long.
You could have them exploring alternate realities. In every one where Dr McKay and Colonel Sheppard are different sexes, they are together. There's even a few where they are girls and happily shacked up. But in all the ones where they are both guys, they are both single. That, unfortunately for Rodney, includes this one.
"Love consists in this: that two solitudes protect and touch and greet each other."
That quote, as well as being delightful and insightful in itself, is spot on for these two: John and Rodney absolutely are two solitudes, Rodney in the prison of his personality, John perhaps by choice, maybe running away from those who would too closely bind him. Let them greet, then protect, and finally touch each other.
I've seen lots of Rodney/John fics where they are in an AU and don't already know each other, and they meet and John is John and Rodney is Rodney, and the problem is that I've never understood why John is supposed to like Rodney. Why Rodney might fancy and like John is obvious: he's pretty and he can be charming. But Rodney is always huffing and blowing and overcompensating and being spiky and unlikeable, and so why would John like him?
Answer: because the plot of the story demands that he does, and that's just not good enough. You end up with something like "There was a twinkle of amusement in John's eyes at Rodney's indignant squawk" or "inwardly smiling at the shocked squeak from the man in front of him, quickly followed by a scowl". I am pretty sure that you need to see past the outward shell of Rodney before you start to like him, and that can't be done without getting to know him. So although for Rodney it might be love at first sight, for John it has to steal up on him. He has to realise that he loves Rodney, and by the time he does that love has to be so strong that he can't resist it (though he may well try).
[Wikipedia:] In the Season 3 episode Irresistible, Sheppard's team found a man called Lucius that everyone in his world adored, but they found obnoxious. Strangely, Dr. Beckett took Lucius back to Atlantis and soon everyone in the city fell under Lucius' charm. John revisited Lucius' planet and discovered he was using some kind of drug that makes the user generate a kind of pheromone that makes people want to please him. Having a cold, John himself was immune to it, but for that he was distrusted by everyone else, especially by Lucius who put him in a cell. John escaped and captured Beckett, who then created an antidote for the drug. John kept Lucius in a Jumper away from Atlantis while Beckett innoculated everyone on the city. After returning Lucius to his planet, John suddenly turned to Rodney and said "Hey, buddy, I'd better get back and clean your quarters before the next scout." before trotting away, making it obvious that McKay took some of the drug himself. Weir, Beckett, Teyla and Ronon immediately told Rodney to burn it all. John's reaction to this was not shown.