[He can't help it, honestly. There's just something about the other boy that brings all of his competitive drive to the surface, whether it's through training or eating or the weird form of banter they've established. So really, why would kissing be any different?

It's not like kissing Titus, and it's not like kissing Izuku or Iida, even if this is something influenced by this place and these moons. This is something entirely new, and honestly? Entirely fun. He doesn't even think about holding back as Katsuki places a hand on the back of his head, and this time it's Shouto's turn to part his lips first, licking at Katsuki's lower lip, then experimentally sucking on it, tugging it between his teeth to see if it does the same thing for him as it did for Shouto. The texture is new, unique, and that's going to take some getting used to, but the taste--oh, he definitely likes the taste. Why does he taste so good? Something seems vastly unfair about that, and at the same time he's definitely not going to question it as long as he gets more. More of everything, in fact. Maybe if he--yeah, that's a little better, possibly. He's just going to tug Katsuki a little more on top of him, looking for more contact, more closeness, as his hands wander down the other boy's chest and then back under his shirt, sliding over his lower back and then boldly exploring further, fingers splaying flat over his stomach as he arches up into that kiss. Why hold back, when they're both enjoying this?]