Calliope and OPEN
Wan, having been convinced to be a scientist by Gracie earlier that day, walked over in a school robe that had been charmed to be white for the duration of the party. Giving it a sort-of lab coat look. The rest of his costume consisted of his normal jeans, a few baggy t-shirts layered as they usually were, and his sneakers. His hair was down and purposely tousled to look like he hadn't brushed it in days and just let it go anywhere it wanted.
He stopped next to her and poked a treat that looked interesting. He poked at it for a while before picking it up and examining it closely. Then he turned to her and said in his best estimation of a 'scientist' voice, "From all visual appearances it should be appetizing. Further testing will now commence."
Further testing, of course, was him popping it in his mouth.