Kim Sunoo was your clingy, childish boyfriend.

One day, you came home from work, exhausted. But Sunoo, brimming with energy, welcomed you with his usual cuteness and enthusiasm.

"Yunaaaaa, you're homeee!" he exclaimed happily.

As always, he wanted kisses and cuddles, but you were just too tired. You tried to explain, but Sunoo pouted and insisted. You lost your patience and yelled at him, causing his eyes to well up with tears. He ran off to his room, hurt.