The biggest scandal in Horace Slughorn's life occurred towards the end of his final year of Hogwarts, ruining all of the carefully laid plans he had made. One day in June, upon seeing his ex-girlfriend snogging some younger Gryffindor Weasley, he threw up several times, very publicly, between the first and his second NEWT exam. Taking that exam, Arithmancy, in a state of delirium, he ended up getting a Troll on the exam (yes, you heard me right: a Hogwarts Professor getting a Troll) when he started appealing to "imaginary numbers" that the professor did not believe even existed. Even though he recovered enough over the next few days to salvage most of the rest of his Newts to a low Exceeds Expectations average, his Troll not only caused both of his employment offers to be rescinded, but caused Gringotts to close his bank account and forbid him from ever opening or holding another account there - or at any other British wizarding bank - again. This is why, even to this day, Horace Slughorn uses fancy bottles of alcohol such as firewhisky and the famous oak-aged mead as a store of wealth: he can legally posess and consume alcohol!

William//Slytherin [200 exactly!]