A/N: My first ever romance - I'm nervous!

Chapter 1

Arthur wanted to be happy. He should be happy. Theoretically he was happy - very, very, happy.

Sir Lancelot had returned to them.

It was nothing short of miraculous, an occurrence even Merlin - Camelot's recently appointed Court Sorcerer - was shocked by. This, he explained to Arthur once they had all recovered from the initial surprise of seeing the noble knight alive and well and standing in the palace courtyard, was the most powerful kind of magic there was. The power of life and death.

"The Triple Goddess." Merlin was beaming fit to burst at the impromptu feast they threw that evening, undeniably happy in a way Arthur envied. "She must have rewarded you."

"What do you mean?"

"You brought magic back to Camelot." Merlin looked across the room to where Lancelot was laughing with the rest of the Round Table. "She gave you a gift in return."

It doesn't feel like much of a gift. The thought flitted through his mind before he could quash it, and he winced at its vitriol.

Merlin, as ever, read his expression with ease. "She loves you, Arthur."

He was talking, of course, about Guinevere. Guinevere who had been happiest of all of them to learn of Lancelot's return and had flung herself at him with tears running down her cheeks. She stood beside the knight now, watching him with a particular look on her face. A look Arthur used to think was reserved just for him.

He downed his drink and plastered on a smile, hoping it didn't look as strained as it felt. "Come on. Let's join the celebrations."

He went to Guinevere's side, wrapping an arm around her waist and trying not to clutch too tightly.

He had never been good with words. He could make speeches, of course, had been trained to orate since he was ten. The thought of those long sessions with his father still filled him with residual dread, memories of Uther snapping at him to stop hesitating, shouting at him when he tripped over the words he was supposed to have prepared. Over time he had gotten better at learning speeches (largely with Gaius's help), but the writing of them still proved a challenge. Merlin had proven a godsend in that respect, somehow able to distil Arthur's scattered thoughts comprehensively onto paper in just an evening. It was a rare skill not even his innate magic could explain.

Arthur wished he had Merlin's help now. It was the morning after Lancelot's return and Gwen was still asleep, her ringleted hair loose across the pillow. Arthur picked up phrases and discarded them again, testing out sentences in his mind and sighing in frustration when they didn't express what he wanted them to.

"Arthur?"

In the shaft of light peeking through the curtains she looked radiant, even half-asleep. He cursed himself that he might have ever taken her for granted.

"What's wrong?"

"Do you love him?"

The question spilled out before he could think to stop it. He hated the hurt look on her face when it did.

"I'm sorry. I just..." I hated the way you looked at him. "I..."

She laid a hand on his bare chest. "I love you, Arthur. Only you."

She pulled him in close and Arthur forgot about Lancelot for the rest of the day.

The following day they had swapped places. He awoke to find Gwen watching him, chewing her lip anxiously.

"Guinevere?"

"I lied." Her voice trembled. "The truth is... the truth is..."

His heart started to tremble too. Perhaps it was shattering. "It's Lancelot, isn't it?"

Tears traced down her cheeks. "I'm sorry."

"Do you love him?"

"I do." It was a whisper, a confession. "I don't want to, but I do."

"And does this mean... Do you want to leave?"

"No!" Her instant outrage at the mere notion served to reassure him, if only a little. "Yes I love him, but Arthur - I love you too. I chose you. No matter how I feel about Lancelot, nothing will ever happen outside of our marriage. I would never jeopardise what we have. Never."

"Are you sure?"

"I love you Arthur. With all my heart."

With all my heart.

It was what she said when he had proposed to her. That was before magic had been legalised, before Lancelot had returned. Would she make the same choice now? Arthur wondered, even as he wiped away her tears and whispered words of comfort. Knowing she might have married Lancelot instead?

Over the next few weeks, Arthur watched Gwen. He tried not to, but it became something of a compulsion. He stole glances from his chamber window as she walked across the courtyard and strained his ears to listen in when she was seated beside Lancelot during meetings of the Round Table. He scoured for any hint of the love she had confessed and, to his surprise, found none.

She did not seek Lancelot out, did not linger over their rare conversations, did not cast him longing looks. As the weeks wore on, Arthur started to trust that she had meant what she said. Yes, she loved Lancelot, but she loved Arthur too. She wouldn't act on her feelings.

So why was he still unhappy?

The answer came to him one restless night. Gwen was asleep, hand still splayed where she had been stroking his chest. She had been extra affectionate with him recently, and he appreciated it; nothing made him feel safer, more grounded, than her touch.

He was thinking back to the day of Lancelot's return. Joy writ large upon Gwen's face as she embraced the returned knight, her eyes sparkling with delight later in the evening as they spoke together. How strange, Arthur thought, that he should miss that sight.

"Guinevere?" He shifted across to light a candle at their bedside. "Guinevere, wake up."

She grumbled a sleepy complaint, but he waited patiently as she came to awareness.

"Arthur? What is it?"

"I don't want to be the person who makes you unhappy."

She peered at him in bleary confusion. "You make me happier than anything."

"But would you be happier," he pressed gently, scarcely believing what he was about to ask. "If you could be with Lancelot too?"

She shifted upright, coming fully awake now. "But I... I told you I wouldn't do anything-"

"I know. And I believe you." He took her hand in hers, considering how best to phrase what he wanted to say next. "It's not unheard of for royals to take... companions... out of wedlock. After all, many nobles don't marry for love."

She squeezed his hand fiercely. "But we did marry for love."

Arthur's heart was trembling again, but then he focused on their interlocked fingers and the sensation eased. Safe.

"I made a promise when we were married that I would spend my life trying to bring you joy. If this could make you happy... if he could... surely it's worth a try?"

She scanned his face intently, flickering candlelight reflected in her eyes. "I don't want to lose you."

Something softened in his heart at that, to know that it wasn't only him who had fears of diminishing what lay between them. He pulled her to his chest and breathed her in.

"You won't."

The beginning was the hardest. They spoke through various permutations of what the arrangement might look like, discussed what they were and weren't comfortable with. How often should Gwen spend with Lancelot and how best to arrange that time? Did Arthur want to be there when the time came to discuss this all directly with Lancelot himself? How private should Gwen's growing relations with Lancelot become, given how such a thing might be looked upon in the public eye?

The conversation continued over the next few weeks, neither of them eager to rush things. In the darkness and privacy of their chambers they grew more candid with one another, raising topics so explicit that they made Arthur blush and Gwen stammer more than she had since her days as a timid maidservant. Would Arthur be comfortable with Gwen kissing Lancelot, lying with him, taking him in her mouth?

"That- that side of things doesn't..." Somewhere nearby an echo of Arthur's father was shouting at him to Stop mumbling! Speak up! "It's the love that matters. For me. I'd just rather not know the uh- the details."

She wrapped herself around him. It was rare that he enjoyed feeling small - as King, he was expected to be big, larger than life even. Here, in their bed, in her arms, he loved nothing more.

"We don't have to do this, you know. I've not said anything to Lancelot."

"I want to try," he reassured her, resolute as always, and they briefly abandoned their discussion in favour of more pleasurable pursuits.

Two months after Arthur had first suggested the shift in their marriage, he kissed his wife goodbye and watched her leave for an evening alone with Sir Lancelot. He would be lying if he said he wasn't still uncertain, but when the uncertainty veered towards panic he reminded himself of all that he and Gwen had talked through.

There was much he preferred not to know. The words she and Lancelot exchanged, the kisses and the touches, the details of their intimacy. What he did know, for Gwen reminded him nearly non-stop, was that none of it would impact the love she held for her husband.

So he distracted himself with matters of the kingdom that evening, losing himself in reports and council agendas, until finally he was so sick of it all that he dropped into bed and fell asleep near-instantly.

The next morning he was awoken by a flurry of warm kisses and a soft litany of loving words. He rolled over and there she was, his Guinevere, a look of such utter peace and contentment upon her face that he knew for certain they were doing the right thing.