When your girl is at the bottom of a very tall tree, spread eagle, waiting on you.
You climb to the top of the tree, naked. Jump off with your back facing the tree. As you're free-falling, you're jacking off and as your dick enters your girl you ejaculate and then plummet to your death.
Yo, did you hear about that guy jumping outta that tree?
Yeah man, didn't he give his girl the ol' alabama backscratcher?
The act of one person taking at least a 13in dildo to the ass, while the pitcher scratches their back until bleeding. The word "sowry" is constantly said during this act.
Uncle Barnebee will take care of you, ask him for the Canadian Backscratcher. You'll walk with a limp for a week.
When Tom Cruise goes on Jay Leno to promote his new movie getting released by Universal Studios which is owned by the same company, GE, that owns NBC. That's Corporate Backscratching my friends!
When you are grinding with a girl, or doing any chest-to-back dance, and you get an erection that is therefore "scratching" her back. Depending on the severity of it and how intoxicated the girl is she may not feel it at all.
Ex. I popped 2 Viagra before coming to the club, girls get ready for the back scratcher.