Why did the Markeys insist that Edith and Ede leave the party?

At the end of the party, Ede suddenly became jealous of Billy's teddy-bear. She approached the boy, yanked his toy away from him, and pushed him to the ground. Because Billy was not injured, Joe dismissed the affair with good humor. However, when Ede pushed Billy again, this time so forcefully he whacked his head on the hard floor, Joe and Mrs. Markey became upset. Ede's sudden outburst of laughter further shocked everyone. Unable to control herself, Edith burst out laughing too. Mrs. Markey insisted they leave at once if they could not be quiet and respectful. Her words angered Edith. She burst out crying and began insulting Mrs. Markey. Joe did not approve of this behavior, and told Edith to calm down. This angered Edith even more, and she repeated her insults. The Markeys insisted she leave.