The line comes from Saturday Night Live's Weekend Update in the late 1970s, when Dan Aykroyd and Jane Curtin anchored the fake news desk as bickering co-hosts. Aykroyd opened his rebuttals with Jane, you ignorant slut before launching into a rant, and the blunt catchphrase stuck. It became one of SNL's earliest breakout quotes, repeated on compilation shows and late-night retrospectives. Online it survives as a vintage insult meme, sampled in soundboards for its shock value and nostalgic network-TV bluntness.