Cataglottism - Kissing with tongue.
Nishinoya was a very touchy person.
It wasn't that Asahi minded that fact one bit though. It was just one of the many things that he'd noticed once they officially started dating. He got more pats on the back, arm punches, and enthusiastic hugs from the libero than before, and Asahi quietly appreciated the attention whenever he got it; whether it was during volleyball practice, or in the halls, or any time they happened to be together, it was as often as possible.
When they were alone was a different story though. They visited each other's homes at least twice a week, and enjoyed short moments of privacy, peppered with soft and light kisses. Noya, despite how much he might've wanted to do otherwise, kept his hands to himself in those moments, never trying to push further than he thought Asahi would be comfortable with.
It was nice, Asahi had to admit, that Nishinoya didn't want to push him too far or anything like that, but after dating for nearly two months with only hugs and handholding and chaste kisses having occurred between them, Asahi was curious to try more.
He got the perfect opportunity not much later, too. His parents decided to take a trip for the weekend, leaving Asahi home alone for those few days, and he gladly took the chance to invite his boyfriend over for the weekend.
…
Winding up on the couch in Asahi's living room with Noya practically sitting in Asahi's lap wasn't originally part of the ace's plan, if it could even be called that. He couldn't deny that it was nice though, watching television with an arm wrapped around his boyfriend's waist and holding hands. The show they were watching kept Noya's attention, but Asahi's focus kept wandering, namely to the smooth skin of Nishinoya's neck.
Once a commercial came on, the tall third year couldn't resist temptation any longer and leaned down to press a soft kiss where he could feel Noya's pulse jump beneath his lips.
"Hey wh-what was that for?" Noya yelped, whipping his head around to stare at Asahi with a bright red face.
"Ah, it was nothing, I just-"
Asahi didn't get a chance to finish his sentence, being cut off by Noya's lips against his own for a moment. Pulling away, the libero grinned and poked Asahi's quickly reddening cheeks. "Heh, if you wanted a kiss you should've just said so!"
Asahi blinked slowly, a little surprised, but running over Noya's statement in his head. He thought for a moment, weighing his chances, and spoke up again just before Noya could turn back around. "Okay. Can we kiss a bit.. more, then?" Asahi asked, watching Noya's eyes widen and cheeks flush slightly.
"Well, ah, sure of course, if you want to that'd be totally cool!" Noya said, a bit louder than necessary with a big grin.
Asahi nodded, setting a hand on Noya's cheek before slowly guiding him closer and leaning in until their lips fit together smoothly, Asahi's upper lip settling snugly between Noya's.
It was a little strange, Asahi thought, how such a little bit of contact made his heart race so quickly. But he knew it wasn't just the contact, it was also being so close to someone he cared so much about. And there was nobody he could think of that he cared about more than the feisty Guardian of Karasuno.
Breathing through his nose, Asahi could feel soft puffs of air against his upper lip as Noya did the same. The warm puffs, oddly enough, helped Asahi gather his courage again, and he parted his lips enough to slip his tongue out and slowly trace along Noya's lower lip.
The smaller male froze momentarily, and it took all of the willpower in Asahi's glass heart to not pull away and apologize, but after what seemed like an eternity, Noya opened his mouth and allowed his boyfriend access. Asahi entered carefully, trying not to get overwhelmed by the taste and the fact that oh god his tongue was in Nishinoya's mouth, and he could feel Nishinoya's tongue against his own.
It wasn't until Noya tilted his head to fit their mouths together better and wrapped his arms around his neck that Asahi felt courageous enough to move his tongue more, slightly surprised by how good it felt just to move his tongue with Noya's.
Unfortunately, it was harder for them to breathe like that, and they had to separate after a minute. Panting softly, Asahi couldn't help but blush when he saw the wide-eyed look of excitement on Noya's face, which he could only interpret that as a good thing.
"Was that.. okay, with you?" Asahi wondered out loud, still wanting verbal confirmation.
"Yeah! And you also liked it too, right?"
Asahi barely nodded before Noya's lips were back on his, and the younger boy sent a silent prayer of thanks that they would have more time alone together to practice what he was sure would quickly become one of his favorite things to do with Asahi.