Because BaekYeol is ~

"Come on, hurry," Baekhyun urged Chanyeol who was in the middle of ing his shirt. "Faster, Chanyeol."

This spurred Chanyeol to move faster, almost tearing out the buttons in the process. 

He then proceeded to his pants, and them, shimmying out of them faster than he had ever done in his life. 

"You better get dressed in these and to the van in two minutes or were leaving without you," Baekhyun warned him, throwing a costume on his bed and rushing out the door. 

Chanyeol stood there in his underwear and wondered if his manager would really leave without him.