Mrs . Myers' face had lost its lemon pie smile, why?

Mrs. Meyers' face lost its lemon pie smile because Jess and Gary were acting up in her classroom.

"Ah, c'mon. Lemme see."
Jess shook his head.
Gary reached down and tried to pull Jess's hand away from the paper. "The Case of the
Crooked- c'mon, Jess," he whispered hoarsely. "I ain't gonna hurt nothing." He yanked at
Jess's thumb.
Jess put both arms over the paper and brought his sneaker heel crashing down on Gary
Fulcher's toe.
"Ye-ow!"
"Boys!" Mrs. Myers' face had lost its lemon-pie smile.