A/N: Warning! Contains smut... Don't say I didn't warn you!
Jack had been sneaking into Elsa's room every night for a month now, simply to talk to her, kiss her, or even simply just to feel her close to him. Having her near made him feel things he hadn't in, well, maybe ever. After being isolated and alone for centuries, he had become more of a loner in the world. He couldn't remember his past and had forced himself to keep moving forward, feeling like time had been frozen all this time. However, now… Now Jack felt like time had finally started moving in the right direction. Elsa, with all her qualms and worries, was the single thing that could get him through his dreadful, lonely life and he was going to hold tight to this feeling as long as he could.
"Elsa?" Jack whispered into the dark bedroom.
"Jack?" Elsa murmured, half asleep. Jack apologized, not realizing how late it really was.
Elsa hummed, sleepily before sitting up and stretching, "Come in, don't leave the window open. I don't want the cold getting in."
Jack stifled a giggle, "You do realize I am called 'Old Man Winter' and you're worried about letting in the cold…?"
Elsa groaned, "Oh, shut up and get over here," she smiled.
"Can't argue with that," he said, closing the window tightly.
He crawled into bed next to her and she instantly wound her arms around his broad shoulders and pulled him close to her.
He climbed on top of her and kissed her desperately, needing to be closer and closer to her.
After a while of this, he ran his hands down her sides and found the hem of her nightgown. He tugged upwards softly, waiting to see if she was going to okay with his actions. He paused at her waist a moment and, hearing no refute, broke their kiss long enough to pull it completely off. He looked at her a moment, realizing she was now wearing only her panties. Elsa blushed and covered her face.
Jack smiled and pulled her hands away before going back to kissing her. He slid his hand back to her hip before slowly moving to her inner thigh, pushing her legs apart slightly. Elsa gasped softly, moving her hips softly into his. She tugged on his shirt, breaking their kiss to pull it off and feel his bare chest on hers. It felt like their bodies were electrified, like the first time they kissed, but this time it was stronger, raging all over both of their bodies.
Elsa had never felt something so intense all at once and it was hard not to let the lust she was feeling take over. "Jack… I need you.." She whispered, breathless.
She unbuttoned his pants and pulled them completely off before kissing him softly, not wanting to ruin the moment by moving too quickly.
Jack rolled over and sat up, pulling Elsa on top of him so that she was straddling him.
Elsa bit her lip and grinded slowly on him, unable to stop herself. Jack groaned and grabbed her hips, moving her quicker on top of him.
Before Jack could take the situation too much further he stopped himself, wanting to make Elsa feel the same sensation he was feeling. He pushed her down on the bed again and put his knee in between her legs, making it impossible for her to close her legs. He smirked, looking down at her, "Damn, you're beautiful."
Elsa blushed and covered her face again.
"None of that," Jack said, grabbing her small wrists in one hand and holding them above her head.
He lightly pressed the tips of his fingers to her chest and traced his way down over her smooth stomach, down further still until Elsa let out a loud moan, arching her back as he pushed two fingers inside of her. Elsa tried her best to stifled her moans, but was finding it harder and harder to as he pushed her to the brink.
Just as Elsa found herself losing control, he stopped and began kissing her again. Elsa whined, begging for him to continue, bucking her hips lightly into his. Jack released her wrists and kissed her neck, biting it softly, before kissing her chest. Elsa watched him with pleading eyes, wanting him to continue where he left off. He pulled her panties off, throwing them to the floor.
He grabbed her breasts and gave them the attention they had been missing before he moved his hands to her hips, kissing her stomach and inner thigh.
Grabbing the back of her legs, he made eye contact before lowering himself to her opening. Elsa threw her head back and grabbed the sheets, bucking her hips with his mouth's movements.
"Jack- mmnn… J-" Elsa tried between moans, "Jack, I can't hold… on much longer, I need you…"
Jack kissed her inner thigh, then he kissed the hollow of her hip before moving back up to kiss her neck.
"What was that?" Jack smiled.
"I need you," Elsa said, her body convulsing in pleasure.
Pulling what was left of his clothing off, Jack readied himself.
"Are you sure?" He asked, waiting for her response. She nodded pulling him closer so she could envelope him in rough kisses again.
He pushed himself in slowly, letting her become used to it as he went. Once inside, he waited an excruciating amount of time, making sure she was completely ready.
Elsa moved her hips slowly, testing her limits. They bucked their hips together, struggling to set the right rhythm until he moved her hips with his, setting a proper pace. Jack grabbed her hips and pulled them down harder, not being able to hold back any longer. Elsa dug her nails down his back, giving in to the pleasure she was receiving. She arched her back and groaned, wanting the waves of pleasure to release her from their lust-filled grasp.
Jack was barely holding on at this point, no longer able to contain his moans. "Elsa… I'm-" he trailed off.
They both dissolved into pleasure, finally ending their wave of passion.
Covered in cold sweat, the two gasped for air, slowly slipping into exhaustion.
Jack sat up, knowing he had to leave before morning arrived. However, Elsa pulled him back down, "It's fine.. Stay… I don't want you to leave me…" She whispered, too tired to say much more.
"Elsa?" Jack said, laying back down next to her and pulling her close.
"Mhmm?" She breathed.
"I- I think that…" He trailed off, too embarrassed to finish.
"I think I love you too…" She whispered, trailing off into sleep.