She was smirking at him, and Walt resisted the impulse to roll his eyes.  "Shut up." He advised, although she hadn't really said anything yet.  "And let's just get this over with."

“Ooop!” she said as it happened. “Guess I reached with too much of my body.”

Walt managed some how to side step out of her way and steady her at the same time.  Did other people have friends who tried so regularly to end up in their laps? 

"Well, the sleeves aren't helping."  With his luck though she didn't have anything underneath there, and he wasn't about to ask.  She might not mind doing homework in her skivvies, but he did.  "Hold your arms out, I'll help roll them up."  With a wave of his wand the sleeves began to neatly fold themselves up to their shoulders.

"Better?  Right, let's try again."  He frowned at her though. "What happened?"