That that wasn't the answer Sirius had been expecting was patently obvious from the look on his face (surprised, uncertainty and a smile behind the surprise fighting for dominance,) though if asked he wouldn't have been able to say what was. Being told not to be an idiot, maybe.
Which would probably have been fair.
As it was, no verbal response seemed really appropriate, and it wasn't often that Sirius Black was lost for words. He ran a hand through his hair again and licked his lips, unaccountably nervous, and then made a small noise of frustration at himself and grabbed Remus's wrist, tugging him to close what little distance the werewolf had left between them so that he could drag him into a kiss.