Fionna and Marshall woke up to loud pounding on their door. Confused and sleepy, they answered to a red faced Prince Gumball, rage and sorrow in his eyes at the sight of them two.
"Gumball? What are you doing here? It's like 9 in the morning, shouldn't you be sleeping too?" Fionna winced at the bright sunlight hitting her hand. "Just come inside, physco." Her pale hand grabbed his collar and pulled him in without consent.
"Why are you banging on our door at this time of day? Are you crazy?" Her eyes narrow but she stays calm. He opens his mouth to speak but tears start to fall. he huddles up in a ball on the couch.
"Just- Just leave me alone, Fionna." He shudders, sqeeezing his eyes shut. "Gumball, what's wrong?" She whispered sympathetically. She sat next to him, shrugging at Marshall. "Just leave me alone." He repeated. His eyes glanced toward Marshall, glaring. "Let me talk to him, Fi..." He pushed her lightly aside and sat next to Gumball.
"Dude, what's wrong. I'll try to help anyway I can." He sighed, knowing he's not helping. "Just explain, buddy. Please." "You can't fix it." He sobbed. "You're in love with her." He blurted out, regretting the words. He blushed, filled with embarrassment. "Wh-What? What does Fionna have to do with this? You guys are so close... and... ugh." She huffed, frustrated. "You don't want us together, do you?" He frowns, conflicted. His sadness turns to anger, "You didn't let me in your room! You hate me! Why should I listen to you, why should I care about how YOU feel? It's not like my feelings matter to you, anyways."
Gumball sniffled, pondering. It's true, but it was all an act, he didn't really hate him, it was just envy and confusion. But it's too late now. He wiped his eyes, clearing away some pain. "Marshall, you have no idea. You know why I was pretending to hate you? I was scared and jealous! I knew you'd never love me and I knew you loved Fionna but I had this tiny sliver of hope that you would choose me... not my best friend. I love you Marshall, it's a shame it took so long for me to admit it.
He stormed out the door, leaving Marshall in awe and staring out the door. He called out for Fionna, he heard tiny stifled cries, he entered the bedroom and Fionna was sobbing, curled up and shaking. "I heard everything. Just please tell me you love me, and that you have no feelings for him." "I promise. I love you, Fionna, don't doubt it, ever."