1) Give me a pairing.
2) Give me an AU setting.
3) I will write you a three-sentence fic.
"What about this one?" Kristoff asked, holding up yet another silver band.
Elsa smiled gently. “Kristoff, that’s the same one you showed me five rings ago.”
Kristoff’s face fell, his shoulders slumped. “Right…I didn’t even notice.”
Elsa fingered the end of her braid, tiredly eyeing the displays upon displays of wedding rings. She had never known her sister’s fiancé to be a picky man; he was always laid-back and relaxed (characteristics she herself so often admired), but they’d been here for what felt like hours, looking at every kind of band, diamond, and jewel imaginable.
"Kristoff, I agreed to help you, not make the decision for you," Elsa said, placing a hand on his shoulders. "This is something you need to do."
He nodded. “I know, I know. I’m just…nervous. What if she says no? I’ll just make a big fool of myself and-“
Elsa couldn’t help but laugh in disbelief. “Are you kidding?” She giggled. “Anna never shuts up about you! Plus she’s been dropping hints that she wants this for months. Do you really think her new subscriptions to Bridal Guide, Martha Stewart Weddings, and Get Married are a coincidence?”
Kristoff smiled, laughing despite himself. “I guess not, but…I’m still scared. I mean, I’d do anything for her, but…I know I don’t deserve her, or anything like that…”
"Yes you do!" Elsa insisted, titling his face to make him look at her. "You’re so good to Anna; you keep her safe and make her smile and love her just as much as I do. And I know you’d never do anything to hurt her; I trust you to that."
She paused, old memories coming back to her like an old friend. “…When were were little, she would always talk about finding her ‘knight in shining armor’. And now it looks like she has. And I couldn’t pick anyone better for her to spend the rest of her life with.”
Kristoff blushed to his ears, unable to hide his bashful smile. “Really?”
Elsa smiled. “Really.”