look up any word, like the eiffel tower:
some fool's idea of a synonym for the word cool.
Baby, you're so awesome, you're sex on fire.
by sinembarg0 March 22, 2009
When sex is really really good.
Man, this is good. This is sex on FIRE.
by Tourettes_Guy December 28, 2008
A Very AMAZING kings of leon song

of there new album (L)
"yeahhh, your sex is on fire"

Boy: Omg Have You Heard Sex on Fire

Girl: Yeah Sex On Fire Is A Awsome Track Of KOL's New Album
by NikkNak ;] November 05, 2008
When a girl with a UTI infection has sex...
(girl with uti infection): i had sex last nite... it was sex on fire
by xX kinky man91mXx December 14, 2009
Guy: I was with this girl last night, SEX ON FIRE!

Doctor: Yeah, you've got gonorrhea.
by SUPERkawaii!! April 26, 2009