THROW YOUR BACK OUT 

it's actually a warning of a great fuck session that one is about to enjoy from a voluptous woman. Skinny women cant do it...you MUST have tits and ass and a lot of confidence; usually comes from either married or divorced women in their thirties, better known as VIPERS.

were going to fuck so long and hard that I'm going to throw your back out...

THROW YOUR BACK OUT by VIPER1 June 26, 2008

throw your back out 

When a guy gives it to a girl so hard her back hurts.

Man that girl over there is so fine. I whispered in her ear and told her im going to throw your back out tonight.

throw your back out by gesshowmanyarethere January 11, 2008