Hyunjin holds out for a good ten minutes before he finally blurts: "I can't believe you and Seungmin hung out today and you didn't tell me."

When Yeji glances over, he's making a face at the red crosswalk signal before looking both ways and pedaling on. She sighs, rolls her eyes, and rollerblades after him. "I mean, that's just the rules of twinhood!" Hyunjin continues, Yeji only catching the tail-end of it behind him. "You can't leave me out of the loop like this!"

"Last time you came to study with us, you almost got us kicked out," Yeji scowls, pushing him lightly with her shoulder so he goes off-kilter for a second. The setting sun turns the asphalt before them orange, blinding. "Last time as in last week. Did you already forget?"

Hyunjin scrunches his nose, annoyed, tilting his head back to push his too-long fringe out of his face. "Hey," he defends. They pass through the shade of the tallest apartment complex in their neighborhood, coloring them in navy for a moment. Not a cloud in the sky today. "I was totally being productive."

Yeji gives him a look. "Hyunjin, you played a rhythm game on your phone full-volume for a good five minutes before you realized your headphones weren't plugged in." And then, after he'd been kicked out, he'd waited outside on the steps of the library, hugging his backpack, and sent Seungmin an I'M BOREDDDD // play with me ㅠㅠ text every five minutes.

"You're ridiculous, Hyunjinnie," Seungmin laughed at the shocked expression on his face when he came out an hour and a half later for some fresh air and plunked a vending machine coffee can onto his head.

Hyunjin had frowned in retaliation. "Too bad you love me," he sniffed, the cicadas chirping around them, air hot and stuffy, typical of a mid-summer noon.

Seungmin laughed at that too with a "You wish," and yeah, Hyunjin thought, looking into the little hole of his coffee can like he could disappear into that caffeinated universe of darkness, he really did. That's when Yeji had stormed out with her own bottle of green tea, made them scoot down so she could sit on Seungmin's other side, and reached over him to hit Hyunjin in the back of the head when he gulped down half of her drink. They all took turns pressing the still-icy-cold bottle to their necks before heading back inside.

Hyunjin, unable to one-up his sister, just sticks his tongue out. Because summer's always been: Hyunjin, Yeji, and Seungmin, and the sweat sticking onto their skin as they walk back home from the convenience store with their Samanco, always teasing Seungmin for eating his tail-first. Watching the same old VHS movies that they can recite the lines to on the same old TV Hyunjin lugged into his already-tiny room the month before their first year of high school because, "He's a pack rat," Yeji whispered to Seungmin when Hyunjin left to use the bathroom. Staying up late to help Hyunjin finish the summer homework he procrastinated on but always ending up falling asleep around Seungmin's kitchen table the night before they go back to school instead, the fan whirring through the cicada songs coming through the open window, oscillating until Yeji wakes them all up at dawn.

Yeji laughs and pushes his head once he hops off his bike. "You're gonna eat a bug if you keep doing that, you know?" She skates past him after he opens the door, even though the neighbors have complained several times about her doing that. "C'mon," she says happily, pressing the elevator button while Hyunjin locks his bike in the racks, grumbling to himself about how she’s so mean when I’m the older twin, "I bet dinner's ready."

Seungmin told Hyunjin one day last semester, when they'd walked home together, too hungry to wait for Yeji's soccer practice to end, that he wanted to be an astronaut. To which Hyunjin, somewhat awed, said: "Can you really be an astronaut if you barely make the time limit for the sixteen-hundred meter?"

Seungmin punched him in the shoulder. "Hey!" he'd cried out, but when they made eye contact, they both started laughing, long and for no real reason. "That has nothing to do with this!" he insisted once he'd finally caught his breath, nudging Hyunjin. And when Hyunjin still didn’t stop grinning, "That has nothing to do with this," he repeated, petulant.

That night, after giving Yeji his and Seungmin's leftover tteokbokki to stop her from chewing him out, Hyunjin spent hours researching astrophysics and the cosmos that the next morning, when he'd overslept and had to lean over to ask Seungmin if he could copy his math homework the period before, Hyunjin saw a galaxy in the familiar curve of Seungmin's smiling eyes. “Fine,” he’d said, placing his notebook into Hyunjin’s lap, “but you owe me,” except instead of exasperated, he’d just shook his head at Hyunjin’s mouthed you’re the best, Seungminnie!, fond. Imagine knowing right then that you were being drawn into an inevitable gravitational pull – that you had been for a while now – and that only a carefully calculated escape velocity would allow you to break free from orbit.

Imagine: the month after, Hyunjin caught Yeji looking at Seungmin in this certain way he’d never noticed before. Like, in the midst of the vast emptiness that is space, she'd seen the bloom of a supergiant in the distance and found herself indescribably drawn to it. Hyunjin didn't realize he'd been staring until Yeji happened to meet his gaze. The two of them understood, in that moment.

Imagine: twin planets, circling a single, gargantuan star in an otherwise lonely universe. And, give or take some, that's just celestial mechanics.

Yeji rounds the corner, coming to a stop before where Seungmin's standing next to his bike, looking at his phone. He locks it, smiles, and puts it back into his backpack. "Did Hyunjin oversleep again?" he asks knowingly as Yeji catches her breath, hands on her knees.

"Yeah," Yeji grumbles. Seungmin offers her his water bottle, still sweating and cold, to which she shakes her head. "I tried to wake him up but he's being a big baby about it." The summer morning sun is bright and Seungmin's laugh is blinding. She shields her eyes from the glare. "That's why I'm late. Sorry."

"Nah," Seungmin says, swinging a leg around his bike. When he turns to face her, there's a streak of unblended sunscreen tracing the side of his cheek. Yeji makes a motion for him to smooth it out and his mouth makes an "o" in recognition before he wipes at it. "Thanks. And I always leave five minutes later when I know Hyunjin's coming, anyway."

Yeji makes a face. "He's gotten that bad, huh?" But the few times Yeji's left Hyunjin behind to be punctual on her own, Seungmin had been waiting in front of his apartment building already, standing next to his purple bike on the side of the road, head bowed as he scrolled down his phone. And every time he heard her skates approaching, he looked up and gave her a toothy grin, and Yeji apologized for making him wait.

Seungmin smiles, open-mouthed. "He's gotten that bad," he confirms, pedaling alongside her, their shadows forming a two-headed monster on the asphalt.

It's funny, sometimes, to think about their lives before Seungmin. Funny because, despite being twins, growing up, Hyunjin and Yeji hadn't been that close at all. In primary school, Hyunjin had his own friends that would play tag with him in the hallways and get yelled at with him by their homeroom teachers, and Yeji would hear them laughing about getting in trouble from where she was sitting by the window in her own classroom, eating the picked-out carrots in her friend's lunch box. And while Yeji got perfect scores on math tests, Hyunjin was always near the bottom of the class. He would ask her once they were home if he could copy her homework, to which she'd just tell him to buzz off, and then he'd go whine to their parents about how mean she was. They didn't talk much apart from that.

When they were in fifth grade, Yeji's best friend told her during physical ed that she had a huge crush on Hyunjin, and it made Yeji cry in the middle of dodgeball. "I'm sorry," her friend said the next day, after Yeji went home and called Hyunjin a head over dinner and he gave her the silent treatment because of it. Serves him right!, she'd told her mom when she tried to get Yeji to apologize. She handed Yeji a fancy piece of chocolate that they both mentioned liking before. "I won't like him anymore if it makes you sad." And while the chocolate was sweet as Yeji nibbled on it, something about it left a bitter taste in and made her feel like the bad guy.

But Yeji technically met Seungmin first. Once they started middle school, and Yeji's best friend moved thirty minutes away by subway, and early on in the school year, she'd been assigned to do classroom chores with him. Seungmin was the type to mop every corner carefully, and while Yeji was wiping the blackboard clean, Hyunjin had thundered down the hall, stuck his head through the window of their classroom, and said, "I'm walking home without you, slowpoke!" before running off with one of his classmates.

"My brother," Yeji frowned when she and Seungmin were rinsing off their washcloths in fountain outside. Seungmin hummed in wordless acknowledgement. "He's always like this."

He laughed at that. "Doesn't sound like you two get along," he pointed out as he wrung the mop dry.

"Yeah," Yeji echoed. The water was warm on her palms amid the winter. "We don't." Except Hyunjin was waiting at the front gate when Yeji and Seungmin got there with his head down, and the three of them walked together in relative silence until they reached Seungmin's apartment building, five minutes away from theirs. "See you tomorrow, Yeji," he waved before disappearing behind the gate. He considered Hyunjin too, who finally looked up from staring at his toes. "Yeji's brother." They waited until the door closed completely before continuing down the road.

"Is he, like, your boyfriend or something?" Hyunjin asked abruptly, once they'd turned the corner.

Yeji rolled her eyes. "None of your business," she'd replied, swinging her backpack over her shoulder after grabbing her keys – the whole reason why Hyunjin had ended up waiting for her in the first place. And the three of them have been walking home together ever since.

Now, Yeji chews on the straw of her iced coffee across from Seungmin, who's leaning back after being hunched over his prep book for an hour. "Hyunjin says he's on his way," he yawns. "Should I get him his drink?"

A drip of condensation from the rim of her cup wets the page of her notebook. Yeji watches as her notes, carefully penned in, bleed around the perimeter. "You don't have to," she tells him. When she uncrosses her legs under the table, she kicks the bag with her soccer cleats in them instead of Seungmin's shin. Recrosses them. "You know, in Hyunjin speak, that means he's only just started showering. And doesn't he still owe you for ice cream last time?"

"It's okay," Seungmin says, already rifling around his backpack for his allowance. "I'm gonna make him owe me so much that he'll have to buy me an apartment in Gangnam someday." He grins at her, like this is a secret between the two of them. "He likes the iced Americano here, right?"

Before Yeji can saying anything else, Seungmin's already walking up to the counter to order. She sighs, tracing the edges of the water splotch on her notebook in defeat. "You don't have to," she mumbles again, quiet, to no one in particular.

At Yeji's first soccer match of the summer, Hyunjin asks Seungmin without much thought: "Do you ever wonder what it'd be like if you liked Yeji?"

Seungmin, whose eyes have been glued to the game the whole time, gaze following the ball back and forth, doesn't turn to look at him. "Like," Hyunjin continues, gesticulating out of nervousness. A whistle blown on the field punctuates his thoughts. "Like like. Have you ever thought about it?"

Seungmin presses his lips together. There's a tiny red bump on his chin where he'd told Hyunjin that he'd gotten a mosquito bite last week, on the side with the mole on his cheek. In the absence of everything else, Hyunjin maps the distance between them on Seungmin's face with his eyes, like some kind of topographical constellation. And then Seungmin says, "Red card."

"Huh?" Hyunjin whips his attention back to the game that he realizes he hasn't really been watching at all, only to find it continuing on. Yeji gets the ball from one of her teammates, shoots, and scores, her ponytail bobbing up and down as they jump together in victory. "What do you mean?"

Seungmin's looking at him when Hyunjin turns back to face him. There's a smile tugging on the corner of his lips that he doesn't seem to want to let spill over. "I mean," he starts. "That I can't answer that." Hyunjin watches as he wipes his palms against his shorts. Sometimes, he wondered what it'd feel like, holding Seungmin's sweaty hand in the midst of the hottest week of summer so far. "You guys are twins."

"Oh," Hyunjin replies. They wave to Yeji, who's grinning at them both from where she's taking a break on the bench. Now Hyunjin feels stupid for starting this whole conversation. "Okay." He really shouldn't have asked.

Seungmin nudges his knee with his own as if to say that's okay. "Did she tell you to ask me that or something?" he questions, taking a sip from his water bottle. He offers it to Hyunjin, but he shakes his head.

"No." The noon sun is bright and overwhelmingly warm against his skin as he shields his eyes from the glare. Maybe that's what holding Seungmin's hand right now would feel like. “She didn’t.” And then Hyunjin's back to wondering.

It rains the next afternoon. Over the alien glow of the first Pokemon movie that they've watched more times than they can count on two hands, the three of them play rock-paper-scissors to decide who gets to run down to the convenience store in the downpour and buy their usual Samanco.

"You guys ," Seungmin frowned once he realized the two of them threw paper. Hyunjin just laughed on the floor of his room while Yeji smiled apologetically and went to go find her umbrella for him. "If I catch a cold, it's all your fault!"

Hyunjin wrapped his feet around one of Seungmin's ankles, the fan blowing his still too-long fringe into his face. "Thank you, Seungminnie," he cooed up at him, trying to hug his legs.

"Gross." But even as he tried to fend Hyunjin off, Seungmin had been laughing too. Yeji started poking him in the back when she came back with the umbrella, tickling Hyunjin enough to finally let Seungmin go.

Without Seungmin sitting between them, the two of them are silent, other than the pouring rain outside and Hyunjin saying, as soon as the door closed behind Seungmin, "I feel bad for making him go."

Yeji shrugged. "Better him than you." She started rinsing the plate they'd eaten watermelon on – Hyunjin always tried to finish his slices as quickly as he could so he could choose the best ones for himself, leaving Seungmin and Yeji with the paler, unsweet ones. "You always buy me the wrong kind."

"It's not my fault that the green tea one goes out of stock the fastest!" Hyunjin insisted, even though that was only once. Other times, the green tea flavor wasn't on sale like the other kinds, and Hyunjin was stingy with his allowance. Yeji just rolled her eyes.

Now, Yeji pulls her knees to her chest. "Hey," she starts. Hyunjin hums from where he's still focused on the tiny TV screen, even though they both know that the VHS skips a little in the first twenty minutes. Their mom told him to throw it out before, even offering to buy him a new one online, but he'd staunchly refused, and they argued about it for a week until Hyunjin cried during breakfast and their mom conceded. He'd gone to school puffy-eyed that day and Seungmin wouldn't stop l