That small noise is certainly not enough to have Lorenz willing to back away, no, if Claude was really done with him he'd have done a good deal more than that. The subtle back and forth of their banter is familiar, even if this particular incarnation of it is new.

At least until Claude's lips part and a moment later Lorenz is jerking back, eyes wide and gasping in surprise. For one frantic moment Lorenz is caught between panic and some strange sort of thrill that makes his heart race. Oh.... is that?

"Oh."

A single, profound realization and then Lorenz presses in to kiss him once more, cautious and curious but doing his best to mimic what Claude had just done as well, shuddering out a breathless little moan when his tongue just barely touches Claude's lip.