This is s derivation of an ancient Assyrian tethering tehnique. It was done in many different cultures. Most recently in England in the 1800s.

You will need a fence with three horizontal bars or wooden slats (circular).

The female places both of her legs through the second fencing bar and wraps the top of her feet under the lowest bar. The front of her upper legs will lightly touch the upper bar and her hands/wrists are comfortably bound to her knees over the opposite end of the fence. She will be bent over and leaning back slightly at about a 30 degree angle.

A man is stand upon a box and mount her from behind. If penetration is vaginal then the technique is called "horsebroke". I will not explain all the derivations of "horsebroke", however, readers can experiment upon this.

If the technique is anal it is called "the pestle and the mortar". There are several dexterity games you can play if it is an anal application.

The most historical is where the woman bounces lightly back into the man as the penis is inserted only two inches into the anus. The male backs away as the female leans forward and the penis is entirely removed from the anus. The female then moves back and the male attempts to insert his penis into anus once more (only 2 inches) before it is removed and done again. The male is not allowed to touch his penis. This is an accuracy/dexterity building technique, designed to train the male for precision during copulation.

If done too quickly at first, or too clumsily, his penis will be bent and he will be punished thereby. His job is to obtain 10 precise insertions. Then 20, then 30 and so forth until he can do this 100 times without error. Each time he accomplishes his goal, he is to make a mark on the female's right buttock cheek (in ancient times they used a stick with cooled ash on the tip). If he fails, he is to place a mark on the female's left buttock cheek. In this fashion a tally is kept for reward or punishment purposes (winner gets this, loser gets that, etc.)

The most important aspect is to insure that the female's anus is adequately open. The couple is to play fair...meaning the female should not try to move sideways. Both partners ultimately end up winning in this loving game of chance.

This is "the pestle and the mortar". It is much more refined and dignified than the technique used by the Assyrians.

In 1800s England this game was called "Pub Darts" and was a game played in rural northern England. This was not widespread, but it was a frivolity for those areas for several decades.