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Admittedly, this could have been avoided. Tadashi could have left the apartment, or he could’ve gone straight to his own room, closed the door behind him, and ignored the fact that his best friend was having sex with his boyfriend next door. He could have done that, but he didn’t. Instead, he found his feet dragging his body to Tsukki’s door, which had been left slightly ajar.
This had never happened before. Tsukki and Kuroo spent most of their time at Kuroo’s place when they were together, because his flatmate was more casual about this stuff. They already had rules set up or something apparently, and unlike Tsukki and Tadashi’s own apartment, the bedrooms weren’t right next to each other. He didn’t want to make Tadashi uncomfortable, Tsukki had said.
So, this was new. And Tadashi knew he shouldn’t do it, he knew it was wrong, but he couldn’t stop his feet as they went up to Tsukki’s door, and he couldn’t close his eyes as they looked inside the small gap between the door and its frame. He found Tsukki lying on his back with Kuroo above him, both of them moving in way that made it all too obvious what exactly they were doing. Tsukki was moaning softly with each move, it seemed, his arms extended behind his head where his hands were gripping and pulling at the bed sheet.
This was bad, Tadashi thought, but his stomach twisted with excitement. This was really, really bad, and he should stop whatever he was doing, he should stop watching, he should stop getting turned on. He should just. Stop.
He watched how Kuroo shifted on the bed, sitting up all of a sudden and almost giving Tadashi a full view of his bare torso. He grabbed Tsukki’s legs, hiking them up to rest against his shoulders, and Tadashi’s cock twitched in his jeans, gasping as he observed the change of position.
He really shouldn’t have done that.
The small sound was enough to catch Kuroo’s attention, and he looked up, eyes staring right back into Tadashi’s in surprise. Fuck. His cheeks heated up and in the moment of panic, Tadashi pulled his bag out in front of him to cover his crotch. Kuroo smirked at him, and Tadashi realised how obvious he was being, feeling even more flustered. Kuroo kept watching him as he snapped his hips forward, and Tsukki moaned loudly under him. His smirk grew wider when he saw how Tadashi’s mouth fell open and his eyes grew wide.
Tadashi quickly backed away from the door and tore his eyes away from the scene, running into the bathroom. He closed the door behind him too loudly in the rush; Tsukki would definitely know he was home now too. Tadashi pressed a hand to his chest, his heart beating so strongly he could hear the sound of it in his ears.
He moved the hand down, palming himself between his legs. His dick was hard beneath the restraints of his clothes and urging to be touched. He shivered as he thought of the way Kuroo had looked at him.
“Shit,” he muttered, tilting his head up to stare at the ceiling.
He had really liked that.
The knocks on his door were soft, but the sound still made Tadashi jolt and he dropped the pen in his hand.
“Come in,” he said and straightened his back.
“Are you busy?” Tsukki asked as he opened the door, not yet entering.
Tadashi shook his head, and Tsukki went across the room to seat himself on his bed. Tadashi swallowed and turned his chair to face him. He could only guess what Tsukki wanted to talk to him about.
“So, you saw us today.” There was no skirting around the topic and he didn’t need to specify what he meant. Tadashi nodded, eyes evading Tsukki’s gaze. A million thoughts drove through his mind, but really, he had no excuse, he’d been trying to think of something, anything, the whole day. He couldn’t explain. He knew he was in the wrong.
“...And you enjoyed it,” Tsukki continued.
He wanted to deny it, but it would only make him feel more guilty, so instead, he answered with a small ‘yeah’ as he clenched and unclenched his hands.
It was quiet between them, and he dared himself to look at Tsukki. He was watching Tadashi with calm expression; he didn’t seem mad, but Tadashi shrank a little under his gaze. He was just about to apologize when Tsukki spoke again.
“Do you want to do it properly next time?”
“W-What?”
“Do you want watch us again, properly this time?”
“I- What?”
Tsukki sighed, growing impatient.
“Do you want to watch us again. Like, inside the room. While Kuroo and I have sex.”
Tadashi blinked at him and suppressed another ‘what?’, knowing it would annoy Tsukki.
“Wait- y-you- are you-” he couldn’t even put together a complete sentence. Closing his mouth, Tadashi stared at Tsukki.
Was he serious? He couldn’t be. This had to be a joke. Right?
“We want you to. If you do...” Tsukki said, sounding more tentative this time.
Tadashi let out a breath he didn’t know he was holding, and finally he nodded, gut twisting.
“Okay.”
Tadashi had almost forgotten about it when Tsukki asked a few days later if tonight was alright, except he hadn’t at all. It was a constant at the back of his mind, popping up whenever his thoughts would wander, but he had been surprised to realise that it really was going to happen.
It was awkward. Tadashi definitely felt like an audience, seated on a chair close to the bed, watching them. He had a much better view there, compared to the first time. Watching them from the side, he could get a fairly clear view of Kuroo preparing Tsukki.
So far, they hadn’t paid Tadashi any mind, not once looking over at him once they had started. There had been very little foreplay, the two stripping as they got on the bed before Kuroo had leaned in and kissed Tsukki. Tadashi had been able to see the exact moment Tsukki had slid his tongue inside Kuroo’s mouth.
Kuroo had guided him to lie down on his back while his mouth moved lower, kissing down across his neck, chest, and stomach. Tsukki had spread his legs easily, letting Kuroo kneel between them while he reached for the lube.
They moved with each other as if they knew exactly what to do. Like it was the simplest thing. Effortless. It made sense, though; they had already done this so many times before. Kuroo pushed a second lube-slicked finger inside him almost immediately after he entered the first one, with Tsukki easily taking it. His breaths had grown heavier as Kuroo opened him up with his fingers, and Tadashi noticed the way his body twitched when Kuroo angled his hand a certain way. Kuroo noticed it too, smirking slightly.
No; the two were already familiar with each other’s bodies. Kuroo probably didn’t have to notice. He just knew.
“Tetsurou...” Tsukki breathed out, throwing his head back.
Tadashi felt his cheeks burn. He had never heard Tsukki use Kuroo’s first name in the past, and hearing it now, in this situation, it felt incredibly intimate. Again, Tadashi became aware that he was an intruder. He felt hot, and belatedly, he realised that he was sweating, the back of his shirt already beginning to stick to the chair he was leaning on.
He diverted his attention to Kuroo, who now had three fingers inside of Tsukki. Tadashi had always admired his physique, and like this, he was able to properly appreciate it. Kuroo was tall, albeit not as tall as Tsukki, and visibly strong, body broad and sturdy with defined muscles under taut skin. He could see how Kuroo’s muscles flexed and relaxed with just the slightest move. Subconsciously, he spread his legs slightly.
As he watched them, Kuroo now withdrawing his hand and pulling a condom over his cock, Tadashi squirmed in his seat, feeling his own dick pulse under the strong material of his jeans. He was so hard that it was impossible to ignore, but- no. He wouldn’t touch himself. He couldn’t, not here. Not like this, right in front of them.
“Don’t tease me,” Tsukki said with a groan as Kuroo pressed the head of his dick against his entrance, not pushing inside.
Kuroo chuckled lightly. “Ask nicely, Kei.”
He didn’t reply right away, breathing heavily, and Kuroo moved one of his hands across Tsukki’s torso until it caught one of his nipples, pinching and nudging it with his fingers. Tsukki writhed at the touch.
“Please.”
Fuck.
Tadashi held his breath as Kuroo finally slid his cock inside Tsukki, only letting the air back out when they began to move.
It was almost awe with which Tadashi was watching them. Each of their movements was so deliberate, the two accustomed to each other and their bodies. They worked well together, looking like they knew exactly what to do to please one another. He saw how Kuroo slowly increased his pace, moving his hips faster, his skin shining slightly in the light from sweat, and he saw how Tsukki pushed his body back against Kuroo, meeting him with each thrust while he clung to the sheets of the bed, body flushed and mouth agape, the moans easily escaping past his lips.
Kuroo grabbed Tsukki’s jaw while he dipped his body, kissing him messily before he tilted his head to the side and forced Tsukki to face Tadashi.
Tsukki inhaled sharply when their eyes met, and his own breath hitched the very same moment. His eyes travelled down Tadashi’s body, noticing his flustered expression and the obvious bulge in his pants. Then his eyes found Tadashi’s again, and with a particularly hard thrust from Kuroo, he whimpered; a sound Tadashi had never heard from him before.
“Yamaguchi...” Tsukki said with a weak voice, still not breaking eye contact.
Tadashi was so hard, it was painful.
With all of his focus on Tsukki’s face, he didn’t even notice Kuroo moving a hand down to Tsukki’s cock, but he saw the exact moment he touched him. He jolted with a loud moan and his eyes squeezed shut, no longer able to look at Tadashi.
“Tetsurou-!”
He came only after a few strokes, cum thick and pale where it landed on his flushed skin. Above him, Kuroo’s movements were erratic, and Tadashi could see it when he came too shortly after, hips coming to halt as he pushed deep inside Tsukki.
Tadashi simply sat there as they separated and cleaned themselves, looking away. He wasn’t sure what to do, whether he should already leave or not. It was hard to think straight and he realised that he was still breathing heavily. His hair felt damp and it clung to his skin, as did his clothes. His dick was hard and craving attention, but he didn’t want to acknowledge it, staring down at his lap where his hands were. He clenched them into fists and pressed them against his thighs while he tried to ignore it.
“Hey!” Kuroo called, and Tadashi whipped his head up to look at him. He was lying on his stomach, facing towards Tadashi and hugging a pillow though he was clearly still naked. “Are you going to do something about that?” He nodded his head, eyes flickering to Tadashi’s crotch.
“Kuroo, don’t make him uncomfortable,” Tsukki said, a slight warning in his tone. He lay down next to him, stealing away his pillow, but Kuroo didn’t seem to mind, simply throwing an arm over Tsukki’s shoulders. They were both watching him now, waiting, and that somehow gave Tadashi a thrill.
He took a deep breath and swallowed as he forced his hands to relax. He lifted himself a little from the chair to pull his jeans and underwear down, his stiff cock springing free.
“Well, fuck.” Kuroo breathed, eyes on Tadashi’s cock. Next to him, Tsukki was quiet, but he was watching him just as intensely. “Are you going to touch yourself for us, Yamaguchi?”
He felt his throat dry. There was something about the look in Kuroo’s eyes when he asked him that made Tadashi not want to say no to him.
His dick was red and throbbing with the tip already wet from precum. He would probably see a stain on his boxers if he checked. He hissed through his teeth when he finally wrapped his fingers around the base, his feet lifting from the floor as he curled his body slightly into himself.
There was another curse from Kuroo, reminding Tadashi that they were still here. Watching him. As if he could forget. He felt his stomach flutter with excitement and he opened his eyes to look over at Kuroo, not even realising he had closed them in the first place.
“Did you like watching us that much?”
Tadashi couldn’t tell if the question was rhetorical or not and gave no answer. He moved his hands in slow strokes over his cock, and it was agonizing, really, but he was too self-conscious to go any faster. He knew he wouldn’t last long either way.
“This side of him looks pretty good, huh?” Kuroo nudged Tsukki with his elbow, and Tsukki nodded.
“Yeah.” His voice sounded unusually low.
Tadashi tried to spread his legs some more, but he whined when they wouldn’t give. With his jeans pushed down to his thighs, he could hardly open his legs any more than this, the thick denim restraining his movements.
“You ever seen him like this before?”
They were watching him, he thought with a shudder, his hand speeding up. They had their full attention on him.
“No. But I’ve thought about it.” He added the last part after a short pause, like an afterthought.
Tadashi’s hand paused for a short moment.
“Oh yeah?” Kuroo asked, sounding intrigued.
Tadashi bit his lip and moved his hand again, not able to neglect his cock for too long. It twitched for his attention.
“Yeah, I used to think about it a lot,” Tsukki admitted. “About sucking him off, fucking him, getting fucked by him…” he trailed off.
“Ah, Tsukki-” Tadashi moaned, fingers tightening around himself while he looked Tsukki into his eyes.
“Ohoho, he’s thought about it too!” Kuroo laughed. He didn’t seem to mind at all, looking evidently amused.
It was true. Tadashi had thought about Tsukki before, what it’d be like.
“You’ve never thought about him before?” This time, it was Tsukki asking Kuroo.
Tadashi shifted his attention to him, and Kuroo hummed his eyes dark. He was watching Tadashi’s hand with a hungry expression.
“I have. He’s cute,” he finally said. “What about you though, or is it only Tsukki?”
Tadashi shook his head. “No... You too...” His voice was weak, breathless, and he paused his hand to squeeze his fingers lightly around the head of his cock, letting his thumb run over the slit. From the bed, Kuroo grinned at him, happy with the answer.
Tadashi was close. He was going to come soon.
He picked up the pace, pumping his dick faster and Tadashi pushed his hips upwards, fucking into his hand desperately. He closed his eyes, unable to keep them open and on his spectators. He knew they were still watching him, could feel their heavy gazes on him, and Tadashi felt a rush of excitement wash over his body, making him moan. He felt so good.
He came hard, throwing himself against the back of the chair as his muscles tightened, and he continued to stroke himself until he was completely dry. Tadashi felt spent and boneless, arms falling to his sides. He opened his eyes and rolled his head to the side from where he heard a whistle. It couldn’t have been anyone but Kuroo. He felt a new blush bloom on his cheeks and he forced himself to sit upright on the chair.
He was still panting, his chest heaving, and he felt hot and uncomfortable in his clothes, his shirt stained by his own cum. It was only a small consolation that it was white. At least it had been a button down and not a tee.
“Told you this would be a good idea,” Kuroo told Tsukki from the bed. Tsukki jabbed him on the side in reply, but he didn’t deny it. He moved across the bed while he grabbed the duvet, throwing it over his body.
“Tsukki likes to cuddle after sex,” Kuroo explained and followed him.
“Shut up.”
Tsukki looked over at Tadashi expectantly, and Tadashi cleared his throat, feeling a bit like a third wheel again as he watched Kuroo close in on him.
“Um… I think, I’ll go shower.” His fingers played with one of the buttons of his shirt. He really wanted to take it off.
“You’re not joining us?” Tsukki asked.
Oh, Tadashi thought with surprise. He hadn’t realised that it had been an invitation.
“Ah- well, uh, m-maybe another time-” He stopped abruptly.
What was he saying? They hadn’t talked about doing a repeat at all. He sounded presumptuous, like he had gotten ahead of himself. This could just have been a one-time thing. Oh god, he was so embarrassing. He opened his mouth to correct himself.
“Okay, next time then.”
Tadashi blinked, looking at Tsukki with a perplexed expression while he snuggled closer to Kuroo, who happily wrapped his arms around him. Tadashi nodded weakly and breathed a sigh of relief, a smile tugging at his lips.
“Next time,” he promised.