Well, she wasn't pulling away from him, so that was probably a good sign. He forces himself to move closer - the trembling wasn't because she was scared, right? Just nerves; she was just as nervous as he was, maybe? - and slowly, carefully closing the gap between them, gently placing his lips on hers.

He didn't move to make the kiss deeper, but didn't pull away either. Sollux was a bit worried she might be offended if he pulled away first.