The first time they kiss, Lev is bumbling with excitement and happiness and it's reflected when their lips meet. It's all clumsiness and Lev's overeager tongue trying to assert dominance which ends up in too much saliva and clashing teeth. While Tsukishima is fine with Lev putting in effort, he doesn't appreciate the ferocity of it all, especially when neither of them had much idea on how to go about with their whole relationship thing.
"Lev— Stop. I said we have to go slow, and that includes kissing." Tsukishima finally hisses out when he shoves Lev's shoulder to get him off. The pathetic whine that leaves Lev's lips is ignored and the expression that flickers across his face is almost tragically heart-breaking if not for the fact that Tsukishima had seen it far too many times for it to have any effect on him.
"… Sorry, Tsukishima… I just really missed you!" It's not quite as awkward when they sit shoulder to shoulder after their mashing of lips but more of a sullen mood that radiates from Lev's entire being and it drags on till Tsukishima decides to set things right.
Tsukishima cups a hand on Lev's cheek to turn his head to face him. "Don't be such a baby, Lev. Come here." And Tsukishima says nothing more before he leans in for their lips to brush against each other, barely touching as their warm breaths mingle for just a moment before their lips are completely seal against each other.
He knows Lev is startled by his initiative, and he knows how stunned he is from the way Lev freezes in his position, the thin line of his lips tightly drawn with tension that stretches all the way down to where his hands are balled into fists and stiffly placed in his lap.
Tsukishima starts with slow pecks as he gradually tilts his head just slightly such that their lips are perfectly slotted together, like matching pieces of a puzzle that could unlock the secrets of the world, of their hearts. The shaky exhale from Tsukishima's nose and the brief tremble in his hands eases Lev of the fact that Tsukishima is just as hesitant and inexperienced as he is and there is a warmth that bleeds and spread across their skin, one that evaporates any remains of the tension that lingered.
Lev finds himself much calmer than he ever was and despite his impatience, he lets Tsukishima go at his own pace, feeling his tongue peek past drying lips to slide across the seam of Lev's own, slowly coaxing past them.
The difference between Lev's first try and this was a far cry. The kiss that they were exchanging now felt so much more meaningful, sweeter; so much more intimate, and incredibly addictive to the point Lev never wanted to part. As he brings a hand up to curl his fingers round the nape of Tsukishima's neck, Lev tugs him closer to deepen the kiss with an appreciative hum that comes out almost like a low purr of a cat.
Their tongues flit against each other, experimenting with the exploration of each other's mouths, awkward and unsure as they disconnect from each other momentarily before resuming. Lev's enthusiasm returned though his fervour is much more controlled through the little things Tsukishima does. From the smoothing of his thumb over Lev's sharp jawline, to the hitch in Tsukishima's breath that draws out a soft moan, and to the abrupt squeeze of Lev's forearm.
It is not till Tsukishima slowly pulls away minutes later that Lev realises how crazily fast his heart his beating, the glimmering emerald of his eyes boring straight into Tsukishima's amber hues, pupils dilated from the intensity of their kiss.
"That was… It was…" Lev has to take a moment to mentally skim through the list of adjectives he knew, his line of thought constantly distracted by Tsukishima's flushed cheeks and half-lidded eyes, a brow raised elegantly as he waits. The silence is sliced through with a yell of "Amazing!" and Lev grins, its effect so contagious that a smile tugs at the corner of Tsukishima's lips.
"Can we do it again? F-For practice, yeah?" Lev's voice is much more mellowed, anticipating even, as he carefully watches for Tsukishima's reaction, perking up when he receives an almost bashful nod that Kenma had once mentioned to him as 'tsundere' behaviour.