Mikey startled at the sound of knocking and then pushed himself away from the desk, checking as he did that he'd wiped all traces of the graffiti. Satisfied, he went over to the door and pulled it open with a smile (because if he was a feeling a little trepidatious about the whole assistant gig, Nate had to be more so).
"Hey," he said cheerfully, waving him inside. "Come in, come in. And before we get to the awkward bit, call me Mikey and always tell me if I manage to get ink on my face or something." It happened from time to time. The first years seemed to have a knack for making things explode that really didn't need to and somehow ink pots were always nearby. "And sorry again to grab you before the actual lesson, just thought it would be good to have a bit of a walkthrough before we faced the hordes. Or um, the sixth years, you know."
Ugh, a slip-up in the first two minutes, not great. He made a mental note to try his absolute best not to call his fifths The Terrors out loud. "Anyway, how much did Schechter tell you?" He was kind of hoping the 'use you as a live demonstration' ground had already been covered, but if not, he had a few slightly more flattering descriptions up his sleeve for the purpose of persuasion.