Genital Tourette's
Similar to Tourette's Syndrome, Genital Tourette's is the cause of inappropriate verbal/vocal outbursts, as well as frequent humping on anything and everything in sight. Sufferers of Genital Tourette's can be either male or female, and may often complain of redness and/or irritation of the genitalia area. This can be caused by the constant touching of oneself due to the urge to rub one out, or it could just be herpes.
We knew he had Genital Tourette's when we found him in the kitchen screaming, "Fuck! For fuck's sake! Somebody fucking help me!", while trying to pry his dick out of the milk jug.