“Schaulust” literally translates to “joy of watching.” Schaulustige are bystanders who watch a brawl, accident or some other incident for their personal entertainment.

"Schadenfreude" comes to my mind, and the proverb "wenn sich zwei streiten, freut sich der dritte" (when two are fighting, the third is the lucky one). But Schadenfreude is more general than what you are describing and the proverb is not quite on spot, because you are not really involved in the story. I'll probably spend the next hour trying to think of a better word ;).