눈치، 빨리빨리، الهواء

눈치 is reading the room before you plant a joke. It is not magic. It is watching whether anyone else refilled the water.

빨리빨리 is speed as manners — don't occupy the gate, the POS, the 김밥 line. It is not permission to be cruel.

If a table goes quiet after you speak, do not double down in English. Switch to 죄송합니다 and let it pass.