Syphilis
A particularly nasty STD, that in later stages causes infertility, leads to your pubes falling out and eventually insanity and death. Friedrich "God is dead" Nietzsche, the German philosopher, caught this from a whore and died. Very common in the midle ages, particularly among the nobility of France. Can be covered up, externally, by a merkin. The US government conducted secret tests on African-Americans in the 30's to see how likely you were to die from syphilis. The Tuskegee Syphilis Experiments didn't end until the 1970's.
Example:
I didn't use a condom when I had sex with that whore and now I have tertiary syphilis, which is making me CRAZY! This is some bad news for my poor wang.
I didn't use a condom when I had sex with that whore and now I have tertiary syphilis, which is making me CRAZY! This is some bad news for my poor wang.