This is NOT how you play hard to get. Say something like "Hmm, I wonder...?"
A flat out rejection is a flat out rejection, even if you want something more.
That's plain stupidity born out of inexperience. Either you are at least mildly interested or not. Interested? Might as well see where it leads. Not interested? Clearly say so. Playing hard to get is the surest way to filter out the guys who respect a "no" aka the good guys. Take a guess which guys remain.
A flat out rejection is a flat out rejection, even if you want something more.