Da steppt der Bär

Literally: The bear dances there

Example: “Am Samstag im Dorfsaal steppt der Bär.” — On Saturday, the party in the village hall will be in full swing.

English equivalent: In full swing

Origin: Traces to a real historical practice: traveling circuses and fairground shows passing through medieval and early modern Europe featured trained dancing bears, taught to perform tricks and move rhythmically to music for paying crowds. This kind of animal training, now recognized as cruel and banned across Europe, actually persisted in various forms into the early 20th century. Wherever a dancing bear appeared, the atmosphere around it was reliably lively, festive, and a little chaotic — exactly the mood the phrase now describes. The specific wording of the modern idiom itself is comparatively recent, generally dated only to the late 20th century, considerably after the actual medieval bear shows it references had already died out.