Kalem-kalem baleman sambuke; mara nyitin ngrepet.[example 1]
Calm like glowing coconut charcoal; but if you light it up, it crackles with a ‘ngerepet’ sound. [proverb] Ngerepet (taleng) is the sound of a crackling fire or a kretek cigarette. This expression is used to describe a person who appears to be calm but, when left to himself and nobody is around, becomes extroverted and active and talks a great deal.
- F. Eiseman - PROVERBS, 1987