The sweat that forms on your balls when you're fucking your sister. May also be applied when fucking your hot female cousin, i.e. incest.
by Bushpig61 September 04, 2010
Man, it was hot out last night! My pants were soaked from the relative humidity when Ida and I came in from the porch.
by John Vanderlay March 23, 2008
Man, I was looking at those family pictures of Helen at Disneyland, I had some serious relative humidity going on in my pants!
by PSA Pilot February 18, 2010
by Anonymous September 18, 2003
by CASEY CARMAN January 23, 2009
It's that little drop of sweat that beads up on the back of your neck and dribbles down your back, thru your crack and eventually drips off of your ball while your fucking you sister.
by Pat May 14, 2003
by Nicole December 14, 2003