The Backwards Slide position is a rather advanced position and works better with a partner with a well proportioned penis.
To get into this sex position, the penetrating partner sits with legs outstretched and the receiving partner squats onto their partner for entry with one leg on either side of the partner. Then the receiving partner leans back until completely supporting their own body weight with hands on the floor.
More About The Backwards Slide Position
This position provides a great view for the seated partner, and a unique angle of penetration for the receiving partner.
For more flexible couples, the receiving partner can grip the lower legs of their partner to move back and forth.
It should be noted that this position carries with it a potential for injury and should be attempted with caution.