A/N: So I have a weak spot for MorMor and a ton of Jim/Seb feels. I wrote this literally so I could have someone dance to this song (Beside You by Marianas Trench) at their wedding. I mean as soon as I heard this song I was like "Wow, great first dance song, I want to cry listening to it," and it's always made me think of these two. It got longer than intended but yeah, one-shot, MorMor, some parentlock (shh, just go with it). Hope you like it… wanted some fluff in the MorMor fics.

Disclaimer: I own nothing except the plot. Sebastian Moran and Jim Moriarty are fictional characters owned by Sir ACD and Mofftiss (yes, they own the BBC series). I don't even own the song. I should really look at my life choices.

It was a cool October day in London and for once, it didn't look like it was going to rain. The cool day turned into a frigid night at an estate just outside of London, owned by a client of one of the grooms. The weather didn't matter though, out here the sky was clear enough to see stars and the couple had made sure that space heaters would be made available to guests.

The backyard was beautiful by anyone's standards, even with the space heaters placed sporadically around the wedding area. The trees had white and blue Christmas lights strung in them and the pond behind the arch where the couple would be saying their vows had candles floating on the surface. All thirty chairs lined up for the guests were equipped with blankets and those little hand warmer things. A young woman in her twenties was situated off to the side with a guitar and a chair to sing them down the aisle. It was simple and almost fairytale like.

This was the day Sebastian Moran never thought would come: his wedding day. Jim would be utterly offended if he knew that was how Seb felt but it had nothing to do with the man he was marrying – Seb couldn't believe he was getting married at all, let alone to fucking Jim Moriarty. Six years ago Jim had been his boss, and then his friend, and then suddenly his lover. Neither man ever really stopped to question the attraction, they just went with it, and Seb had never been more grateful for anyone in his life. Jim may have been a pain in the ass but he was Sebastian's pain in the ass and he wouldn't have it any other way.

Besides that Sebastian couldn't believe they'd found thirty people to invite to this thing. He was barely on speaking terms with his family and he wasn't even sure if Jim had any family left. They did, however, invite Sebastian's friends from his time in the military (the ones who had fallen into a similar line of work), Jim's friend from Uni (who knew he knew how to make friends), some clients to keep things proper and their kids got to invite one person each.

That was another thing Seb couldn't believe (this whole day felt like a dream to him, honestly): Sebastian Moran, an ex colonel who now kills people for a living, and James Moriarty, the world's only consulting criminal, had kids together. Well, not together together. Three years ago the sniper had gotten a call from his high school girlfriend and surprise, guess who was the father of a (then) fifteen-year-old girl? Him.

As you can imagine that went over tremendously well with Jim – a kid person, really. He hadn't threatened to blow up the flat when Sebastian told him but he did have to talk Jim out of killing the girl. Eva ended up living with them after her mother passed. That was almost two years ago and things had gone surprisingly well… nobody had been shot and Jim found he enjoyed talking with Eva.

And then because the universe has the worst sense of humor ever, last year Jim's estranged sister died out of nowhere and her son Alex was left as an orphan. Jim figured since he was such a good dad to Eva (they didn't have the heart to correct him) they might as well take in Alex.

He was a lovely boy, really, but he was just so much like Jim it drove Sebastian mad sometimes. He looked like him too. Every once in a while Sebastian will walk into the kitchen still half asleep and see the teenager sitting at the table and think it was Jim when he was seventeen. They'd taken to treating him just as they had Eva when she moved in: a bit like their child but more like they were their own person and they trusted them. They usually didn't trust them, Jim almost always had Seb follow them when they went out, but the kids didn't need to know about that.

Eva walked over and tapped her father on the shoulder, "Dad are you alright?" Sebastian had been staring out the window in a daze, thinking about this weird day and how bloody happy he was, for about twenty minutes now and Eva wasn't sure if he'd moved during that entire time. Which to be honest, wouldn't be that weird. Seb was a sniper, he was trained to stay still for a very long time – but it still freaked Eva out sometimes. He didn't feel the tap so Eva smacked him on the arm, "Sebastian! You alive?"

He practically jumped and frowned at his daughter, "I thought I asked you not to call me by my name." He'd never admit it but he actually really liked it when Eva called him dad. It made him feel important, like he'd accomplished something with his life. "What's with the violence?"

She rolled her eyes and pulled his shoulders so they were standing face to face and fixed her father's tie, "You're supposed to be out there in five minutes. Wanted to make sure you weren't getting cold feet." Eva stood on her tiptoes and fixed her father's hair (damn her mum for being so short).

Sebastian couldn't help but laugh and smile at her mothering. When his daughter stepped back Seb held out his arms and did a little spin, "How do I look? Think Jim'll kick me out of bed?" Eva made a face at the mention of her dads in bed together, "He hasn't yet. And you look smashing." They were interrupted by a knock on the door and Alex stuck his head in, "Guys I think Jim wants to start sooner. He said he's getting bored." Sebastian cleared his throat and clapped his hands together, "Right then. Alex, do me a favor and keep your uncle from shooting anyone please. The last thing we need is Lestrade to show up."

The teenager smirked and backed out of the room and Eva followed him, needing to go put the proper dress on before walking down the aisle. She was Seb's best man (he'd allowed her to wear a dress) and Alex was Jim's.

The sniper sat on the bed in the giant room for a few minutes before walking out to the backyard and up the aisle, saying quick hellos to the guests as he walked. The man who would be marrying them had been Jim's Priest as a kid in Ireland (again, who knew he went to church growing up). Father Dominic (or Father Dom as he liked to be called) was standing under the archway when Seb walked up and extended a hand for him to shake, "You take care of James. I may be a priest but I'm no saint." Sebastian smiled and shook the old man's hand, "That is the plan. Oh I know Father Dom. Jim's told me stories."

Father Dom's response was cut off as Eva's friend with the guitar started playing and Sebastian's children (shut up Jim, Alex counts) started walking down the aisle towards the front. Eva had insisted on picking the music for their walk down the aisle, complaining that the wedding march would be illogical since there was no bride or some rubbish. They let her choose because they knew she just wanted to pick the music for fun.

Vanessa, as Sebastian would later find out the young woman with the guitar's name was, played "Fix You" by Coldplay as the wedding party came down the aisle. Since there were only two people in the wedding party each kid was escorted by their date. Eva and her boyfriend Dan walked out first. Dan brought her over to where Sebastian stood and kissed her cheek before sitting in the first row. Eva's dress was a muted green dress from the 1950's that made her look far older than Sebastian would ever like. Then Alex and his boyfriend Hamish walked out and Hamish directed his boyfriend to the other side of the arch before sitting down in the second row of chairs (Jim still wasn't thrilled they were together, let alone that he was here).

The music didn't change as Jim came out of the house in a Westwood suit (obviously) and a crown. Sebastian had tried to talk him out of the crown but Jim insisted. His response every time Seb asked him to rethink it was "Honey you should see me in a crown." It made Seb want to punch that smug little smile off his face but not right now. Right now the smile on Jim's face was enough for Sebastian to almost cry. Jim almost never smiled and meant it but the smile on his face right now? If that wasn't the happiest Seb had ever seen his boyfriend…

The criminal's smile got even bigger when he saw his sniper standing at the end of the aisle and he ran towards him, not even caring that this was supposed to be a "moment" as Sebastian had called it. His sniper opened his arms for Jim and laughed as the smaller man almost tackled him with that damn manic smile on his face. Jim kissed his sniper, for once completely happy and content with where his life was and not bored.

Father Dom cleared his throat as the guests decided whether to laugh or melt from the cute. Jim blushed and pulled back from the sniper. He looked almost like a little boy as he apologized to the priest for this sudden outburst. Sebastian had been sure it wasn't possible but in the last couple minutes, he'd fallen even more in love with Jim. He grabbed his hand and was rewarded with a squeeze from his Irishman.

The ceremony had been edited by the couple to keep it short and to the point. The only thing they'd actually changed was that they had each written their own vows. Neither man would ever admit it but they got teary eyed during the each other's vows. Before they knew it, Father Dom was asking the kids for the rings and declaring them husbands. They kissed and somehow ended up back in the room where Seb had been getting dressed before the ceremony, both a little dizzy and wearing gigantic grins.

It's now almost midnight and Sebastian is finally getting to breathe for a moment as he watches his new husband dance with his daughter. They're smiling and seem to be talking about something that is embarrassing Eva, who's blushing. Jim's probably complimenting her dress and telling her that if she ever wears it again, he'll set it on fire. She looks so grown up it's terrifying. The bartender interrupts his train of thought by setting the glass of whiskey on the rocks next to his arm and Sebastian takes it gratefully. Damn that's some good stuff.

"Testing, testing… can everybody hear me?" Alex is standing on the stage where the band is and looking incredibly awkward. Eva probably put him up to this. "It has come to our attention," he gestures to Eva who is now standing at the base of the stage with Alex, "That the lovely couple haven't had their first dance yet."

Sebastian is blushing like mad, hoping they haven't spotted him by the bar, and looking around the yard for Jim. Maybe they can duck out before they get pulled into this. Alex clears his throat up on stage and continues speaking, "Seb stop trying to hide, we see you back there. Your husband would like you to come onto the dance floor please."

Everyone at the party turns and looks at Sebastian almost simultaneously, making the sniper want to crawl into a hole and shoot them all. One of his buddies from the military is pushing him forwards towards the dance floor and Sebastian is trying to talk him out of it, keeps promising he'll pay him if he just breaks his foot right now so he can't dance.

Jim is standing in the middle of all the guests and smiling at his new husband who is literally being pushed onto the dance floor. He actually looks scared which is something new for Jim; he's never seen Sebastian scared. "What's the matter Sebby, afraid you'll step on my toes?" He steps forward and grabs the sniper's hand, dismissing the friend who'd helped him with a nod of his head. "May I have this dance Sebastian?"

"What the hell are you doing Jim?" Sebastian hates to do dance. He avoids it like Jim avoids the dentist and vegetables and acting like an adult. Jim licks his lips and squeezes Sebastian's hand, "Do you trust me Seb?"

It's an almost ridiculous question because usually the answer is no, Sebastian doesn't trust Jim and Jim doesn't trust Sebastian, but something in his husband's eyes makes Seb nod. "Of course."

Jim signals to Alex and Eva who are now standing by a record player and they put on the record Jim had chosen for their first dance as a surprise to Sebastian.

When your tears are spent on your last pretense

And your tired eyes refuse to close and sleep in your defense.

The first two lines of the song aren't even finished before Sebastian knows what song this is and he catches himself before he cries. This song, this damn song, is so bloody perfect. Jim had heard it in a coffee shop when they were on a job a few years ago in Canada, of all places. He'd run back to the hotel with the CD and forced Sebastian to listen to the song. He'd been confused why Jim was so excited about a song, Jim never even showed any interest in music that had actual words to it, and then he'd explained it. Jim said that he'd run back because a week prior, when Seb had told Jim he loved him for the first time, he hadn't known how to say it back. It wasn't something he did. But this song, this song was everything Jim couldn't say to his sniper. That night they listened to the song probably fifty times.

When it's in your spine like you've walked for miles

And the only thing you want is just to be still for a while

If your heart wears thin, I will hold you up

And I will hide you when it gets too much

I'll be right beside you,

I'll be right beside you.

Jim pulled his sniper in closer and wrapped his arms around Sebastian's chest, almost hugging him as they danced together. "Remember this song tiger?"

When you're overwhelmed and you've lost your breath

When the space between the things you know is blurry nonetheless.

When you try to speak but you make no sound

And the words you want are out of reach but they've never been so loud

If your heart wears thin I will hold you up

And I will hide you when it gets too much

I'll be right beside you

I'll be right beside you

Sebastian nodded and smiled down at the man he loved more than anything in the world at this moment. More than his favorite gun, more than a good whiskey, more than the feeling after shooting someone.

I will stay.

Nobody will break you,

Yeah.

Trust in me, trust in me.

Don't pull away

Trust in me, trust in me.

I'm just trying to keep this together,

Because I could do worse and you could do better.

Jim whispered the last line to Sebastian. It had been the line that had always stuck with Jim the most. 'I'm just trying to keep this together, because I could do worse and you could do better,' perfectly described the way he felt about their relationship. He had no idea why Sebastian loved him – he certainly deserved better.

Tears are spent on your last pretense

And your tired eyes refuse to close and sleep in your defense.

If your heart wears thin I will hold you up

And I will hide you when it gets too much

I'll be right beside you

Nobody will break you

Sebastian never cried. Hated crying. He said he did it enough when he was a kid and didn't know how to fend for himself, he didn't need to do it anymore. But this bloody song, it always made him cry, because the way Jim had explained it… it was probably the closest to sentimental that James Moriarty would ever get. And so as the last lines of the song were sung Seb leaned down and kissed Jim, letting that say everything he couldn't.

If your heart wears thin I will hold you up
And I will hide you when it gets too much
I'll be right beside you
Nobody will break you.