"Or very early." he said, almost playful if it wasn't for the utter lack of tone with which he'd said that. Sure Draco was a prefect, etc, etc, but Theo wasn't concerned about his being caught. He would have been pleased to know that Draco saw him as harmless, even more so to know that the way he spoke similarly disarmed people.
He wasn't into brutal frontal attacks or vicious backstabbing ones the way his father was; he played in ambiguity and unknown reference and waited and planned.
He watched Draco with minimal interest but didn't seem to want to say anything more than that.