At first he kind of huffs, but honestly it was... really quite clever. A part of him is very proud of Dedue for that. So the smile creeps back up his face quickly.

"Cheeky." He says, amused.

"Very well. A round of drinks for a very clever man." He's still going to give Dedue a little splash though. "What will the others think when they find out you threw the professor like a shotput?"