So the double back is when you are completely naked and your chik gets completely naked on the bed. You get out the shower, or not, and you jump up and down twice, and catch your penis underneath your legs, tucking without hands, and then you're left with what is known as a GOOTCH, or a cooter.......From the backside however, it looks like you have a hemmorhoids.....You have your girl spectate, maybe even score you like a gymnast, 10 if done correctly, and that is what is commonly reffered to as the double down or the double back. I have yet to do this, cause my penis is like an ASIANS, but I hear the rumors, and it takes serious talent. Disclaimer: if you don't have a chik, anything will do, a dog, a brother, a mom.....