No matter how good Umbridge's temper was, she surely couldn't take being tormented every three days and messed with every five, not to mention turning the entire Hogwarts school upside down—let alone the fact that Umbridge herself was hardly someone with a mild temper.
To an Umbridge with an obsessive need for control, the chaos brought to Hogwarts by Fred and George was simply unbearable.
However, after a long time, once the novelty wore off, playing battle of wits against Umbridge grew somewhat tedious, especially for the Weasley twins, whose minds were now entirely set on opening a joke shop in Diagon Alley. By now, the two had completely broken into the market at Hogwarts and only wanted to get the shop open to fulfill their dream.
Chapter 1017