Scorpius had been waiting for Albus outside the Ravenclaw common room. And maybe, if Albus had known that, he'd have suspected something.

He falls in step with the other boy almost as soon as he appears.

"Hi," he greets, quite cheerfully, "We're skiving off class today."

And since Albus had promised, before he can think of a way out of this, Scorpius grabs him by the strap of his book-bag and starts leading him off in the opposite direction of the classroom.