When Hitler so successfully lied to Chamberlain concealing that he had already mobilized the German army to attack Poland, he asked for a time-out from their meeting. With his generals who had been witnessing his most successful lies, Hitler went into an anteroom, where he reportedly jumped up and down with joy, and then having reduced his duping delight, he returned to the meeting.

https://www.paulekman.com/blog/duping-delight/

edit: for context: Munich Agreement [Wiki link]