that rocky mountain spotted fever

Meaning: In medical terminology, Rocky Mountain spotted fever refers to a very serious rickettsial illness spread to humans by ticks. However, the countrytawk meaning is very different; "that rocky mountain spotted fever" is a slang term referring to any form of sexually transmitted disease.

I know Luann is purdy to look at, but you need to steer clear, my friend. If you mess with her, you'll end up with that rocky mountain spotted fever.