Mad cow disease

When a girl lies about her ex/one night stand to her friends to try and embarrass him when her claims are usually 100% bullshit

Girl: you know dat Tyreese?
Friend: the one you hooked up with?
Girl: he got himself a babydick

Tyreese's friend: I hear you got you a babydick
Tyreese: hell no she got that mad cow disease fo sho