Schadenfreude [shahd-n-froi-duh]: noun
satisfaction or pleasure felt at someone else's misfortune.
It shames me to say that I have occasionally fallen prey to the sin of schadenfreude. Better practice the pronunciation a bit on this one before you teach it to your kids.
"I tell you, Honey, I never thought I'd see the day when a son of mine would hit someone with a toy, then be so shamelessly full of schadenfreude about it." (sigh comes here)
Paul's smirk of schadenfreude nearly betrayed his plot to feed his roommate the laxative 'vitamins'.