In 1945, Mao Zedong and Chiang Kai-shek met in Chongqing to negotiate a peace agreement between the Communists and the Kuomintang.
During the meeting, Mao Zedong deliberately used colloquial language and made jokes at Chiang Kai-shek's expense.
Chiang Kai-shek was a highly educated and sophisticated man, and he was used to being treated with respect. Mao Zedong's behavior made him feel uncomfortable and out of place.
Some historians believe that Mao Zedong's intention was to undermine Chiang Kai-shek's authority and to show that he was the more powerful leader.