Yuya's kiss isn't at all any more nuanced, so he doesn't quite catch onto Gon's struggle. What he does notice is the push back, and his heart just about jumps out of his chest. He hadn't done it with assumptions, good or bad, but it still fills him with elation to have it returned and confirmed. This is something new, which makes is equal parts anxious and exciting--but you don't get anything if you don't go forward and try, right?

It's somehow harder to break the kiss when either of them are actually moving, stuck in a rigid and awkward position. But Yuya finally leans back, just a bit, and looks up at Gongenzaka. But before he can say anything Gongenzaka yanks him forward into an embrace. He's a little thrown off, but when he can take a deep breath he laughs vibrantly and holds on tight.