He did indeed stay, because he knew she liked having him around. He'd realized early on she was afraid of her powers, such wonderful powers, and he fought to change that. He could see she wasn't born naturally with the ability to control them, and no one had ever attempted to help her. It was slow going, though. Even letting them out more than what she had even done an inch of to create the house had her breathing deeply, and one day she ended up crying.
"I froze my whole room after my parents died. I didn't let my sister in; she needed me, but I was too caught up to let her see. No one knew; I had to keep it a secret."
He noticed when he finally decided to hold her, she didn't object.
They had soon fallen into a comforting pattern. He was almost passing the line with the comments toward her; she let herself go a little. They quickly learned they enjoyed each other's company, and Jack felt something with her he had never felt before. It was such a connection that the thought of leaving now physically hurt him.
It was days later, but Jack wasn't sure as they all bled into one another, when she stopped eating her dinner and she scrutinized him.
"How old are you?" she questioned, setting down her fork. Jack bit his lip, as he'd been hoping to avoid this.
"Seventeen...ish." He couldn't lie to her; she could have seen through it.
"Ish?" She repeated, pressing.
"Give or take a couple decades." He attempted to stay causal, and he saw her eyes widen. "Well, you can't expect Jack Frost to be mortal, can you?"
"No." She looked at him, nodding, "I suppose not." It seemed to be an acceptance of his being, and he grinned wide.
"How old are you, m'lady?" He asked. Elsa smiled.
"It's not polite for a lady to say." She winked at him for the first time, and his whole body shuddered with want.
"C'mon, I told my real age." He leaned over the table until their noses almost touched. He noticed the blush that crawled up her alabaster skin.
"I'm 21," she admitted after a long moment.
Jack sat back on his chair. "Sweet Loki, I'm cradle robbing," he moaned with laughter.
"What's that supposed to mean?" she asked, her cheeks turning even brighter red.
"It means I'm falling for a woman much too young for me," he said with a sly grin, and Elsa stood.
"I need to...the front foyer...the falls need...fortifying." She stuttered suddenly, forgoing her dinner and exiting with a swish of her blue gown. She would be back, he knew it.