When a male farts with his legs closed and the warm air escapes forward and slides past his nuts, sliding the testicle to the side and out into the open.
Unknown to my wife I just let a nutslider go. Man does it feel weird at the end when it pops out.
"When the wild Gurshiesty got the gurdepression he planned to gurslide on his ops" (present tense)
"When the opps pulled up Gurshiesty Gurslid on them" (past tense)
"When Gurshiesty wanted to panty senkai he started Gursliding his way over" (future tense)