Sylvester Stallone's Wife Jennifer Flavin -- He Has Never Said the N-Word Ever

Sylvester Stallone wouldn't say the n-word to anyone -- paparazzo or otherwise -- so says the man's wife ... who tells TMZ, she's known him for 25 years and he's NEVER ONCE uttered the slur.

Jennifer Flavin was at LAX earlier today when we asked about the video we posted last week, showing Sly gesturing at a black photographer and saying what sounds like "This f**king n***er here, this f**ker."

But Flavin says everyone heard wrong -- and insists her husband's a good guy.