It would be difficult to miss that there was hidden meaning in Blaise's words. Obviously he was not to know what was in the box. Rather, it was that Blaise would refuse to comment. However, as curious as Draco was, he caught the undercurrent well enough.
He nodded, "Of course. The party." He allowed his lip to turn upwards in a partial smirk as his eyes twinkled. Blaise couldn't begrudge him a bit of levity, could he?
"I'll enjoy watching you fawn over Daphne as Pansy was squirming in discomfort," he teased. After all, it gave a bit of credibility to the interaction and a reason for Blaise to hide it here.
That all of it was true was the important point. That none of it related to what was likely in the box was of no import to anyone but the two in the room.