Jongdae supposes he really shouldn't be surprised when he hears Shang and Jongseok whispering about their plan to launch their baby sister from the slingshot they've made out of the swing into Shang's waiting arms, but he can't deny a certain sense of dread. And maybe a little curiosity, but good parents don't let their children make cannonballs of their younger siblings, so he squashes that feeling quickly.

He turns around slowly, savouring the look of fear on both of his boys' faces as they realise he heard everything. “Hand your sister over,” he says pleasantly, holding his arms out. Shang guiltily s the one-year-old into his father's arms, looking away shiftily. Jongdae's lips twitch, and he's glad that Sunhwa's stubby little ponytail is hiding his mouth.

There's a pause, and then in one split-second movement, they turn on one another, Jongseok's finger almost ending up his brother's left nostril. “It was his idea!” “No, it was his!”

Jongdae coughs to hide the snort that's threatening to erupt, supporting Sunhwa's tiny bottom with one hand so he can use the other to separate the two boys. “Okay, I don't care whose idea it was – “

“Jongseok was the one who turned the swing into a catapult!”

“Shang was the one who said we should use Sunny!” Jongseok says, outraged. He's tiny in comparison with his nine year old brother, but it doesn't stop him squaring up to him as much as he can. Shang stares down at him, unimpressed.

“Alright,” Jongdae clears his throat, pushing them away from one another once more, “I'm not mad.” Well, he would have been if they'd actually gone through with it, but he's just going to pretend that was never going to happen, for his own peace of mind. As it stands, he's going to call it childish curiosity – and dare he say it, ingenuity? – while gently dissuading them from ever doing it again. Supernanny would be proud.

Jongseok's mouth drops open, shock apparent in every feature. He knows daddy can sometimes be the more indulgent parent, but this is not normal. He shares a worried look with his brother, Shang shrugging his shoulders as an indication that they should just go with it. “You're...not?” He asks cautiously, wondering if he can hide under the sandpit lid until bàba comes home.

“No, I'm not.” It takes more effort than it should to keep from laughing. Sunhwa whimpers a little, the plaintive dada a reminder that it's almost time for lunch, and if he doesn't feed the kids on time, it will literally be like having a horde of hungry piranhas on his hands. “I know you two are...” He bites his lip, looking for a suitable description that isn't along the lines of 'out of control'. He settles on “adventurous, but you could have seriously hurt your sister. Is that what you want? She's only a baby.”

Sunhwa burbles along with him, as if reinforcing his point. He's not sure she's saying any actual words, but hey, maybe he can claim she's traumatised and guilt-trip her brothers into behaving for the rest of the day. “See?” He bounces her softly, as if comforting her. “She's scared.”

Jongseok's lower lip wobbles, his eyes huge. He's a troublemaker – he has been since he was born – but he's never been able to deal with the idea that he's done something bad. He flings himself at Jongdae's legs, clinging on for dear life. “I'm sorry, daddy!” He wails, hiding his face in his father's jeans; Jongdae leans down to pat his head awkwardly.

“Shang?” He Jongseok's hair, staring at his eldest son coolly. “Do you have anything to say?”

The apology sticks in Shang's throat – he's never been very good at admitting he's done wrong.“We weren't really going to do it,” he mutters, shuffling his feet defensively. He refuses to meet his father's eyes. “It was just a joke.”

A joke, his . Like how it was 'joke' when he caught them trying to use a needle and acrylic paint to give Jongseok a tattoo. He shudders at the memory; sometimes he wonders if his children are misguided geniuses, or just your everyday, garden-variety sociopaths.

He's hoping for the former. It looks a lot better on university applications.