See, Kurapika can believe that, partly just because Leorio of all people wouldn't be putting off sex unless he saw a reason for it. It is, in Kurapika's opinion, a stupid reason, because Kurapika is doing just fine and doesn't need a checkup, but it's why this is happening to begin with.

He raises an eyebrow sardonically, which would probably look slightly better if he weren't having to twist around awkwardly to peer at Leorio over his shoulder. "Then what was it? Because if that was meant to be foreplay, it seemed awfully professional for you."