Because the prompt "Marceline learns just this one thing in German" was way too good to pass up.
There are things Marceline knows. Such as frets and strings and music and notation and computer science. These things she gets. They make sense to her and contribute to the little fact pile thrumming in her brain. These are the things she's good at, the things people know she's good at and that she enjoys.
Then there are the things Marceline doesn't know. Like politics or sports or science or whatever strange theorems are currently floating through Bonnibel's mind. Actually, Marceline doesn't get Bonnie either. She'd like just a little bit of insight on that topic.
Which segues nicely into her next point: that there are things she wished she knew. Number one on that list is what's going on in Bonnibel's sciency little brain. If someone ever gave her the 'Handbook On Understanding Bonnibel Bennet' her life would be complete. She also wished she understood foreign languages, because it kind of scares her when Bonnie and Rosie start speaking Korean in her presence (are they talking about her or what?). German might be nice to know too because she's pretty sure Bonnie insults her behind her back.
Then there are the things Marceline knows will bore her to tears. Maths is the first thing that pops into her head and its massive shadow kind of blots out anything else. She's sure there are other things she doesn't need or want to know, but right now, mathematics is what she's got. And it will do, it serves her purpose right now.
The problem with having all this rattle around in her head is the knowledge that at some point, she might have to confront it. This was just one such time. Marceline was not happy about it.
"I'm sure there's an easier way," she huffed, spinning a pen through her fingers. "I don't need the history of the universe or any of that. I just need you to help me do this one thing."
The woman she was addressing (a pompous self-possessed witch, in Marceline's humble opinion) stared at her flatly. "There is no in-between," she snapped. "You must learn the basics before you can master anything else."
Marceline slapped her palm flat against the table, eyes lidded. "Look, woman," she started. "I don't care about any of this other garbage. I just want you to tell me one tiny little thing. It's literally all I need and then I can go about my business, have a wonderful evening and you can stop speaking to me. Don't you think that'll be better all around, hm?"
It was blinking this time, albeit with absolutely no emotion whatsoever. Was this woman secretly a robot? Marceline continued to watch her, patient (or as patient as she could manage right now anyway).
At length the infuriating woman sighed. "Fine," she exhaled. "Here." She pulled Marceline's notebook towards her, snatched the pen away and scrawled across the paper a single sentence. Then she pushed the book back at Marceline and walked off, the pen caught in the wrinkles of the page.
Marceline found herself staring at it now wondering how the heck that was even something she could get her mouth around. For about an hour she was just sitting in the back corner of the library hoping somehow she would get the words out right later. It wasn't until her phone beeped that she even looked at the time.
"Shit," she swore, bouncing to her feet, completely ignoring the text from Keila. It would take her maybe ten minutes to get home (skidding on the doormat and eating carpet added perhaps thirty seconds) and probably twenty to shower and get dressed (but only if she could find something she liked without ripping her closet apart, in which case it'd take twenty-five). She was cutting it close.
Bonnie was with Rosie and Marceline was very careful when she parked outside her place, doing her utmost to retain a semblance of calm. Hopefully it worked. She hastened to the door, took a deep breath and knocked.
Rosie answered. She lifted an eyebrow, glanced at her watch and stepped aside. It was all very dramatic.
"Yes," Marceline sighed. "I'm like three minutes late. Just take a chill pill for me."
Rosie wisely maintained her silence. Bonnibel bounded from the bedroom (she'd been sent here to get ready because apparently it wouldn't work any other way; Marceline wanted to strangle Rosie for the suggestion). And Marceline was gobsmacked. Bonnie in blue was… wow. Bonnie in blue with that big smile on her face was too much for words. Marceline decided not to try; she'd just stand there a moment being in awe of her girlfriend and leave it at that.
Once she'd shaken herself free of the spell, Marceline hurried Bonnie (who voiced shrill protest at being basically manhandled, but Marceline was impatient) outside and away from Rosie's knowing smiles. For good measure, Marceline glared at Rosie. Of course, it didn't take Bonnibel long to realise that they were going back to Marceline's place (well, their place technically, they did live together).
"Um…" she began. Marceline waved her to silence. The words from earlier were running circles through her head and she had to concentrate on them or she'd forget.
She held the door for Bonnie when they got home and wished she hadn't because the look on Bonnie's face was mostly obscured from this angle and would've been worth seeing. The room was clean (clean – Marceline had actually cleaned, cue applause). The table was set, food laid out, candles, the works.
"What's the occasion?" Bonnie asked as she sat.
"You're amazing and I wanted to do something special," Marceline replied absently. God but remembering this was so hard.
Bonnie smiled, confused. "Are you alright?"
"Yup. Just uh… I'm fine."
After her failure at eloquence, the meal passed mostly in silence. Bonnie kept glancing up at her and smiling softly. She didn't try to start a conversation and for that Marceline was honestly grateful. This was going to be hard enough as it was without having to navigate a verbal mine field.
Bonnie made to help with the dishes, but Marceline shooed her off. "Sit on the couch. I've left something there for you. I won't be long."
"You're going to an awful lot of effort tonight," Bonnie said wryly. "What did you do wrong this time?"
"Nothing. Promise. Just relax."
Marceline didn't clean the dishes; her hands were shaking so hard she'd probably break them all. She just stacked them by the sink. Naturally, she had to pause to collect herself because her heart was racing in a way that couldn't have been healthy. Her breaths came in ragged and she had to really fight the urge to panic-vomit.
Calm, she told herself. Be cool. Just chill, remember. You'll be fine. This is easy. You have words and you don't even have to speak them the right way. Calm.
She sucked in a lungful of air and headed for the living room. Bonnie smiled at her when she sat down and the nerves fluttering around in her stomach vanished. Forget butterflies, she had freaking bald eagles flapping around down there.
"When did you buy this?" she asked, tapping a nail on the case of the documentary series Marceline had bought. It was something about disease and immune response (things Marceline didn't know anything about). But Bonnie had been harping on about how it wasn't showing in their region and it was an injustice.
"A few weeks ago," Marceline replied, shifting uncomfortably in her seat. "I put a note in my phone so I remembered to buy it."
Bonnie frowned and Marceline realised that was the worst thing in the world. "Okay, really. What happened?"
Marceline twitched. "Nothing. I just…"
Do it now.
So she did.
Marceline slid off the seat (not very gracefully either, upsettingly) and onto the carpet. She pressed pause on the documentary. Bonnie's eyebrows went up questioningly. She opened her mouth.
"No stop," Marceline cut in quickly. "Let me. I'm stubborn and irritating and not very punctual and I can't keep a space clean for long. I'm childish and speak without thinking a lot of the time and I make bad jokes. And you." She took a deep breath, trying to keep eye contact with a still very befuddled Bonnibel. "You're perfect in every single way. You can put up with me for one thing, which is really something, and you sing when you think no one's listening and you don't mind having an afternoon where we bake and everything goes to pot. You're the most amazing person on the planet and I try so hard to be good enough. So today, I learned something."
Bonnie's frown had reversed. Her eyes were so wide now it would have been comical if Marceline's heart hadn't been plotting an escape from her chest. Marceline thought she might've begun speaking, but she just rode over the top.
"I learned something," she repeated. "Just for you. Okay?" She took another big deep breath and prayed that she'd remembered this right. "Willst du heiraten mich in dem morgen?"
And Bonnie's mouth fell open. Bonnie's fingers wound around Marceline's arms and pulled her back up onto the chair. Marceline's heart was not happy with this delay.
But Bonnie was smiling now and that made everything better. Right?
"Yes," she said. "To the first only. Not to the second. I think a little longer might be nice. For planning and such."
Marceline blinked. "First?" she enquired. "Second…?"
Bonnibel laughed. "Do you know what you asked me?"
"Yeah. I asked you to marry me in German."
"You asked me to marry you in the morning," Bonnie chortled. "Which I won't do. But, given a longer time frame, yes. I will marry you."
Marceline's brain chose that moment to go blank. "R-Really?" It seemed wise to double check.
Bonnie shifted until she was sitting in Marceline's lap. "Of course. I wouldn't have you if you weren't obstinate, immature and tardy. That's just how I like you." Her fingers danced across Marceline's cheek as she spoke. Their faces were so close that Marceline really couldn't be expected to concentrate.
Well… she wouldn't concentrate on talking, put it that way.
There were things Marceline didn't know. And things she wished she did. But one thing she knew for absolute certain was that Bonnibel loved her. And, if it were ever asked of her, Marceline would give her the world.
A wedding was nothing.
This is one of very few things I know how to say in a foreign language. My friend in high school used to sing this as she danced through the corridors between classes. She had more than a few 'yes's. Then again, she also professed in German once to 'have a lot of money and want to buy a knuckle duster' so I'm not sure what to make of it.