When Taehyung trips down the stairs on his way to Jungkook in the kitchen, Jungkook laughs before rushing to Taehyung's side, he shakes his head with a smile on his face and says, "You're an idiot."
When Taehyung got Namjoon's curse (of breaking things) and accidentally breaks his phone while filming for their MV, Taehyung runs to Jungkook to tell him the bad news. Jungkook giggles before telling him, "You're an idiot."
When Taehyung sleeps beside the younger, arms wrapped tightly around Jungkook's waist. Jungkook couldn't sleep, so he did what he usually does when he can't sleep, stare at Taehyung who had drool seeping out of his mouth, snoring cutely, too. Jungkook smiles, wiping Taehyung's dirty water and whispers, "You're an idiot."
He doesn't say "I love you." like a normal person. Instead, he'll laugh, shake his head, give you a little smile, and say, "You're an idiot." If he tells you you're an idiot, you're a lucky guy because he loves you, even though you're an idiot.