The trouble is, Arthur and Gwen are so noble about the whole 'we can never see each other again' nonsense. Every time Merlin asks Gwen how she's holding up, she just replies that it's for the best, that she would never be the cause of a rift between Arthur and his father, no matter her feelings on the matter.
Elyan, meanwhile, snaps that her life is worth a damn sight more than any man's affections, prince or not. He was still pretty bitter about being away from Camelot while this whole fiasco had happened.
Arthur vows that he will not put Gwen's life in danger again, no matter how great the temptation to don a cloak and sneak down to her house may be. Both he and Gwen seem remarkably sanguine about their situation whenever Merlin asks them, so it seems that it's left to him to do their fretting for them.
Merlin hates this. He hates knowing that there is a great future awaiting them that seems many years away, an unbearable thought every time he finds himself in contact with Uther, forced to ignore his hate and not-quite-quenched desire for vengeance. Speaking his mind to the king, just once, had felt fantastic, but it doesn't change things for anyone. Then there is the question of Morgana, and Merlin still has no idea at all what to do about that one.
Arthur and Gwen, on the other hand. That, he might be able to do something about.
He has dinner with Gwen and Elyan about once a week - mostly for the company, though the fact that Gwen's cooking is a sight better than Gaius's helps too, not that he'd ever admit as much. They talk about the news of the town, the people Elyan's making things for, the latest gossip from the servant's quarters in the castle. Spending time with the two of them is refreshingly normal, and something of it almost reminds Merlin of being back in Ealdor.
When Elyan returns to the forge to clear up for the night, Merlin starts washing plates and Gwen sits at the table, lacing her fingers together.
"How is Arthur?" she asks hesitantly.
"Oh, you know. He's all right, spends most of his time beating his knights up, same old." He frowns, not sure if that's the right answer. "He misses you like mad, obviously. And he hasn't forgiven Uther, you know, even though he keeps up appearances."
Gwen shakes her head. "I don't want that, not on my account."
Merlin gives her the side-eye. "Well, it's hardly your fault, is it?"
Her mouth quirks. "No, I suppose not."
Merlin towels off the last pot and returns it to its hook by the fire. "I should probably get going," he says. "Think Arthur's dragging me hunting tomorrow."
"Lucky you," Gwen laughs, getting to her feet and coming over to meet him at the door.
"See, are you still sure you're missing out? I don't know if I'd want to spend much time with Arthur voluntarily."
He's joking and they both know it, so Gwen just rolls her eyes and pulls him into a hug. "Try not to get accidentally speared tomorrow, won't you?"
"That was one time," Merlin protests. "But I'll do my best."
Gwen smiles, and kisses his cheek. "Give that to Arthur, from me," she says.
It's only after Merlin's left her house that he wonders how exactly he's meant to do that.
He broaches the topic the next morning as he's dressing Arthur.
"I had dinner with Gwen last night."
"Oh?" Arthur's voice is casual, but Merlin sees the way he straightens up a little, eyes trained on Merlin as though he's only just noticed him. "How is she?"
"She's fine. She asked after you."
"And what did you tell her?"
"That you miss her, but that you're all right." Merlin hesitates for a moment.
"Merlin? Is there something else?"
"Well. She asked me to give you this."
He's standing right in front of Arthur anyway, so it's easy to lean in a little closer and press his mouth to Arthur's cheekbone, softly the way that Gwen had. He pulls away, half-expecting Arthur to throw something at him, but Arthur's eyes have gone soft.
"Oh," he says. "Um. Tell her, thank you."
A little less nervous now, Merlin raises an eyebrow. "Thank you? That's it?"
"Yes. Come on, we should get going."
That's all Merlin gets until two days later when he casually mentions running into Gwen down in the kitchens that morning.
"Mm," says Arthur, thoughtful. "Well, when you see her next, I have something you can give her."
"And what's that?"
There's a wicked glint in Arthur's eye, and so really Merlin isn't too surprised when Arthur curls his hand around the back of Merlin's neck and leans in to kiss him. What is surprising is the way that Arthur is slow and gentle with it, not at all the way Merlin would have thought.
Not that he's thought about it. Much.
"Think you can manage that?" Arthur asks as he draws away.
"I'll -- er. I'll see what I can do."
"You do that."
He catches Gwen at the outskirts of the marketplace and draws her into a corner. It's pretty clear that she knows what's coming, so Merlin does his best to replicate Arthur's approach to kissing. It's actually easier than he would have thought, and Gwen certainly seems pleased.
Everything escalates after that. Of course it does, Merlin thinks, because this is his life and that's typically what happens.
Gwen's the first one to slip him some tongue, but Arthur's the first to take his shirt off (Arthur's always the first one to take his shirt off). Soon enough, he's using every creative skill he possess to best describe the feel of Arthur inside him as Gwen lowers herself onto him, her eyes bright and huge.
Both of them are so beautiful, and Merlin loves them so much that something twists in his chest and he doesn't quite know what to do with himself. He doesn't mind that when they're with him they're thinking of someone else, because he wants to give them this happiness and it's one small way of messing with Camelot's stupid and outdated laws.
Not to mention, it's been far too long since Merlin was having sex this regularly, and he's really not planning on complaining.
"You know, this is stupid," he says one evening, flushed with a stupid-happy grin across his face and sprawled next to Gwen.
"What do you mean?" she asks, sounding a little anxious.
"Oh, no," he says, cursing his poor choice of words. "This isn't stupid. This is fantastic. It's just -- it's really stupid I have to act as a go-between you and Arthur. I am more than happy to, believe me, but."
"Do you have a suggestion?" Gwen asks, propping herself up on her side. The moonlight outlines her figure, and Merlin takes a moment to reflect on what a lucky bastard he is.
"Do you trust me?"
"Yes," she says slowly. "But I don't fancy taking risks."
"It'll be risk-free, I promise. Listen, I know the guards around Arthur's chambers, we can trust them. They're more loyal to Arthur than they are to Uther."
"Hmm," says Gwen. "You make an interesting argument."
"Meet me outside my rooms after dinner tomorrow," he says, kissing her forehead. "I'll take you to Arthur."
Gwen shows up in the pink dress, looking a little nervous but mostly pleased, and it's more than worth the subtle magic Merlin does behind her back to bring the two of them together again.
He hasn't told Arthur, and the look on his face is perfect, a mix of surprise and love and a little awe. Merlin understands that feeling - it's how he feels every time he looks at either of them.
He's about to make an unobtrusive exit when Arthur looks over at him. "Don't think you get away so easily," he says.
Gwen reaches out and grabs his hand, pulling him towards them. "Did you really think you were just a substitute?" she asks.
"Well," Merlin falters. "Yes?"
Arthur and Gwen exchange a look.
"What?" Merlin asks.
"Come here," says Gwen, positioning him between them.
Arthur wraps his arms around Merlin's waist while Gwen kisses him, before kissing Arthur over his shoulder.
"Oh," Merlin says. "Well. All right then."
Arthur takes their hands and draws them back, various accoutrements and items of clothing falling forgotten in their wake. As it turns out, there is more than enough room for three.