Trussed upside down and forced to cum. I love the chin strap on the ball gag that wraps around her neck to make sure that she can't push it out. (sound in comments)
A shrimp tie is a type of Kinbaku bondage. It originated over 300 years in Japan as a torture and interrogation technique. Due to the forced bent-down position of the upper body, this position sends a burning sensation through the body if the subject rema