"How anyone could get so stupid in such a short time!" Who says this offensive line?

In the episode "Greg Gets Grounded" Mike prohibits Greg from driving the family car, but Greg still borrows a car from his friend. While in a discussion with his brother, Bobby, Greg decides to be mean, and call him stupid.

Asked by Vasilii Kulev · Last updated 5 years ago · 218.4K views · SOURCE