[ it occurs to him that he has not entirely thought this encounter through— is it customary to kiss back in such a situation? perhaps he should do so anyway. yes, that seems to be a practical option. and so he does, rather chastely, though there is a degree of intensity behind that austerity and vague uncertainty.
suffice it to say that he hasn't been kissed in quite a while, and may have forgotten to a degree that is is actually quite pleasant. ]