A/N: This one shot was written a little while ago for Sifki Week 2017 Day 1 Prompt: Secrets

Summary: The night before her intended wedding to his brother, Loki finds Sif alone in the ballroom...

"Dancing alone this evening, are we milady?" The young prince asked wryly as he approached Sif.

Upon hearing his voice, she turned and smiled slightly, despite the line of tears on her cheeks. "Loki."

"How fare the wedding preparations?"

Her smile faltered. "Tedious."

"Mm. Have you been practicing dancing?"

"Indeed. The queen is concerned that, as she put it, the guest will mistake my dancing for a battle between my legs and the fabric of my skirt."

Loki smirked, folding his hands behind his back. "It is not you, milady, that she should worry about. I've had the pleasure of dancing with you. It was far from unpleasant. If anyone should be practicing, it is my oaf of a brother."

"Well, we were actually...practicing together."

"Ah."

A moment passed.

Then, Sif started, "Loki, I believe if we told the queen about us she would be understanding-"

"No. Not until I've spoken to my father. He was the damned fool that insisted on you marrying Thor in the first place."

"Then let me speak to him!"

"I told you I would speak to him myself. It's best his wrath only fall upon his son, rather than-"

"And? Have you yet spoken to your father?"

"I...no."

Squeezing her eyes shut, she sucked in a shaky breath and turned away from him. "The wedding is to be tomorrow, Loki."

Unable to find a comforting word, he simply stood on the steps and looked at her.

She was breathtaking.

Standing in the middle of an empty ballroom, surrounded by flickering, golden candles and painted ceilings, she was the most beautiful sight. The embroidered, white wedding gown which wrapped her muscular body cascaded to the floor in flowing ripples. And her dark hair was twisted up, dressed with red flowers.

Shaking his head, Loki moved his hand slightly and gentle music began to play.

"What are you doing?" Sif sighed.

With intense determination, he walked down the stairs until he stood directly behind her. Then, he placed one arm securely around her waist and took her hand. "Helping you practice."

Head leaning back to rest against his chest, Sif allowed him to lead her in a waltz.

Loki had always been a talented dancer, graceful, confident, and smooth, but he found little pleasure in it until he had first danced with Sif. With any other partner it was simply mechanical motions done in unison. But with Sif, the dance was a conversation. An intimate message communicated without words. A silent expression of trust and affection. A flirtatious competition in which the pair tried to outdo one another subjectively in leading and being led.

With a swooping step, Loki spun Sif away from him, only to pull her back so that they were facing each other.

They paused as the magicked music slowed to a stop and a new piece began.

Sif stared up at Loki with regretful longing in her eyes.

And, unable to resist, he leaned down and kissed her.

She responded almost at once, giving up on the next dance and wrapping her arms around his neck.

They allowed themselves this moment of bliss, before the gravity of their actions dawned on the duo.

Once they had separated slightly, Sif breathed, "Damn it."

Loki chuckled ruefully in response, brushing her cheek with his thumb.

"You laugh, and yet I remain engaged to your brother." Stepping out of his embrace, Sif shook her head.

"He does not love you," stated Loki plainly.

"He does."

"Oh?"

"Indeed." She began to walk up the steps, but he caught her arm and pulled her back to face him.

Jealousy flickered through his vividly green eyes. "Really? Tell me more of your grandiose affair."

"He has treated me with nothing but cordiality and respect since-"

"Cordiality and respect! Well, I stand corrected. It sounds as though you two are quite the passionate couple."

"If you would let me finish-"

"Oh no, I think I have heard quite enough, milady." With a mock bow, he took her hand and kissed it briefly. "I wish you and your man well."

"No, you have not heard enough, because I have not said enough!" Now the young woman's face was alight with frustration to match that of the prince. Gripping his wrist, she spoke, "Now you listen to me. Perhaps Thor does not love me in the same manner as you, but he and I are bound together now. And he has told me that he will honor our arrangement with pride. So I intend to do the same."

Loki opened his mouth to speak but seemed unable to find the words. A broken mix of anger and heartache etched across his face.

Sif swallowed roughly, "I do not think it is a wise idea for us to see each other anymore."

Loki scoffed, "Well, as you are to wed my brother that may be challenging."

With a defeated sigh, Sif turned and gazed out of the massive pillared windows, watching the moonlit curtains float in the draft. "What do you want me to say?"

They both remained silent for a moment, letting the weight of their topic dissolve in the sound of their mingled breathing.

Then, Loki sighed. "Run away with me."

Sif started. "What did you-"

"You heard me correctly. Run away with me." Marching to face her, he grabbed her hands. "Sif, what's stopping us?"

"First of all my engagement-"

"Damn that, we both know Thor may have his choice of many other eligible women. He will not long be without a bride"

"And then there's the matter of planning a whole elopement in an evening, and escaping without Heimdall's knowledge-"

"Leave that to me. I know of passages off of this realm which even the gatekeeper cannot see."

"And what of your future?" Bridging the gap between them, Sif took Loki's face in her hands, eyebrows creased. "Loki, if we do this you abandon all chances of ever having the throne…"

He paused and stared at her, gaze softly determined. Then, he took her hand from his cheek, kissed it, and breathed, "What care I for the throne if you are not there to share it with me?"

"Loki…" She gave a tearful, disbelieving laugh. "I know you say that this day, but what about a hundred years from now? What about a thousand?"

"If you remain by my side a thousand years from now then my answer will not change. You know me better than anyone, Sif. You know the strength of my resolve. I rarely regret that which has passed. I have only ever regretted one thing," he placed a hand on her waist, "and that was failing to ask for your hand decades ago."

She beamed at him sorrowfully. "And...you are sure that Thor will not be hurt by my abandonment?"

"I believe you will find that my brother will be relieved, rather than wounded. As much as he respects your friendship, I know he desires no more than that. And if I may say, his lack of that desire makes him all the more a fool."

"Then we would leave tonight?"

"This moment."

"And flee Asgard's soil?"

"-to Nornheim. Or Midgard."

"I cannot imagine the king would take kindly to the news…"

"And that only makes this plot more appealing."

"You are serious about this, aren't you?"

"With all my heart."

The warm glow of the candles illuminated Sif's eyes as her smile grew. As a warrior, she had never been one to shy away from adventure or risks when the gain was worthwhile. And this was both, with more to gain than any battle she had ever fought. So, with a disbelieving yet self assured grin, she nodded. "My prince, I accept your proposition."

The words had barely left her mouth before Loki's lips were on her's. And as her feet left the floor and he spinned her, smiling into the kiss, she knew this was a decision she would not soon regret.