AN: Here's why it's rated higher than K plus.
The loud thud alerted Princess Bubblegum. She looked and saw the Vampire Queen, Marceline in her chambers.
"What the Glob! Marceline!?" Princess Bubblegum shouted in surprise. Marceline was still on the floor having been grounded by the impact of her break in. She then got up her feet and scrubbed the candy dust off her pants.
"Sorry, for the unexpected visit, its hard to get invisible through a huge crowd" She explained as she wiped the dust off her shoulder.
Princess Bubblegum was annoyed, that was no excuse to come in uninvited. "Why did you come here? Marceline!" She demanded.
Marceline simply smiled, she was used to the shouting. "Chill chill, I needed to tell you something, I forgot to tell you this sooner" Marceline said ever so calmly. Princess Bubblegum listened and hoped this was good news. "Ice King turned to Simon, you know: his old self, to attract you, I suppose he already did his move?" Marceline said uncaringly, Princess Bubblegum was surprised and she briefly glanced at Simon's letter.
"Yeah..." PB answered near embarrassingly. Marceline nodded, she noticed the letter PB glanced at and took it. "Hey!" Princess Bubblegum shouted as Marceline read it.
"This doesn't sound like the Ice King I knew..." Marceline commented, the feeling of freedom hit her again, it was getting stronger. She resisted it, she was blushing as she read the letter. "Well, if you're up for it, you can go marry Ice King as Simon" Marceline chuckled. Princess Bubblegum was annoyed, she finds Marceline's attitude quite distasteful.
"I'll just go order the guards to take him away, this was the second time he had to trick me" Princess Bubblegum said frustratingly. Marceline examined her nails and chuckled.
"Everything's going according to plan..." Marceline thought in her mind, it was a strange thought, it was as if she and her subconscious thought of it together, is it because of saving Princess Bubblegum or fighting for Simon?. Marceline had the thought and she was about to freak out but she hid it in a chuckle.
"Why are you chuckling?" PB asked, she thought that this better not be one of her pranks.
"Oh... nothing, I just saved you" Marceline answered with the hint of boredom. Princess Bubblegum was a bit flattered.
"Fine, I owe you one, can you go now?" Princess Bubblegum said half-heartedly. Marceline smiled and she whisked out of the window. Marceline smirked, her subconscious took control of her again.
"Yes, he's mine now" She suddenly thought, her eyes quickly widened. "What the hell did I just say!?" She resisted thinking of the purpose of telling Princess Bubblegum of Ice King's change, it made her feel strange in the inside of her mind, as if she wanted something to happen.
Meanwhile, in the inn.
Ice King was eating at the inn's lobby, the food was of sweet bread and sugared water. He was thinking of what Princess Bubblegum thought of the letter. "Hmm... I wonder if she would like it..." He thought, he had high hopes of the letter succeeding.
The inn was peaceful until the door wrecked open and six banana guards started to abruptly march in. "By order of Princess Bubblegum, Simon, you are exiled from this kingdom!" The banana guard on the front declared. Ice King was dazzled, he was quickly hauled by two guards and was thrown out of the castle's gates.
Ice King landed with a big thud on his bottom, it nearly broke his glasses. "How the heck did they know it was me?" Ice King commented as he rubbed his cheek and wiped the dust off his legs.
"Because I told them" A familiar voice spoke.
Ice King tilted his head up and saw Marceline floating as a silhouette in the center of the moon. "What? Why!?" Ice King demanded answers.
Marceline hovered downwards to his level to get her voice projected easily, "You can't marry Princess Bubblegum because she doesn't like you, she knows who Simon is, Ice King! I told her that a long time ago!" She answered. Ice King was shocked, he didn't know that. "And besides, it's not the evil wizard who wins the princess" She continued.
It gave Ice King hurt, knowing that everyone brands him a bad guy, "Oh... guess I'll be lonely, again" Ice King remarked with a deep frown on his face, he started to walk towards his kingdom in the distance. It felt the same again, he fails and he simply returns to his kingdom, it was average for him; this time though, it felt more hurt for him.
Marceline felt some pity, she did not know exactly why she stopped Ice King plan, it just came into her mind to stop him, was it for the good of PB? Or something else... it lingered in her mind.
Marceline then landed down to ground level. She approached Ice King and grabbed his wrist again. "Where are you going?" Marceline asked, Ice King sighed and let go of Marceline's grip.
"Back to Ice Kingdom, to be with Gunter. I need plot out a new plan, besides, I'm the bad guy" Ice King said sadly as he looked out to his lair, as if it was calling for him. Marceline sighed and felt guilty, she realized that she had to do something.
"Ice King, do you want to come at my place for awhile?" Marceline offered, she slightly blushed. Ice King faced back and raised an eyebrow.
"Why?" Ice King asked being a bit confused. Marceline started to examine her fingers, feeling a bit embarrassed.
"You know... when two lonely people meet and the other asks and..." Marceline's cheeks reddened, she shouldn't have stopped at the last part, thinking that she was implying an innuendo. Ice King's reddened as well, his red was obvious on his cheeks, he decided to just go with it and see what happens.
"Uh... Yeah, I would spend the night there, yeah..." His voice fainted as he scratched his head.
Marceline grinned, she was still embarrassed by her own words. Sometimes, it wouldn't bet her blasted subconscious anymore. "Well, let's go" She quickly bolted to the air and grabbed Ice King by his collar. They headed straight for her cave.
After a good ten minutes, they landed at the entrance.
"On foot from here..." Marceline said as she let go of Ice King. The cave was more darker at night and the moonlight was the only source of light making the inside visible.
As they walked to her house, Ice King had to ask, Marceline's abrupt offer made him seemingly worried. "Hey, uh, Marceline," Ice King called to her, Marceline faced her head towards him, she had the curious look on her face.
"Is this a friendly visit or a..." Ice King stopped to pause, too embarrassed or scared to continue.
"A what?" Marceline asked, wanting him to continue.
They were already at the front of her house. Ice King blushed and continued. "A d-different kind of visit" He stuttered as he continued, Marceline reddened again as they entered the house. The lights were still off. Ice King carelessly walked to the center, he thought that Marceline would open the lights. Marceline floated towards him and held his temples with both of her hands, she made her head go closer and positioned her mouth just beside Ice King's right ear.
"What if I told you it was a 'different' kind of visit?" She whispered, it wasn't her subconscious anymore that was talking. It was coming directly from her, she felt so different for Simon, he seemed to be so much more appealing, the young body and the gullible personality caught her attention now.
Ice King's eyes peeled open, his whole face was blushing out. Marceline felt so different. "Marceline..." Is all he can say, she floated away from him and opened the lights. Ice King's eyes were wide open staring at Marceline, he never encountered a situation like this and was never prepared for it.
AN: Updated, multiple typos spotted and added a bit more story.