On their own each girl doesn't weigh a whole lot. But when the three of them together are standing on the slave, he starts to realize that his bones are enduring quite a bit of weight. His hands are tied to his sides so that they don't get in their way, allowing the girls to stand wherever they want. They stand, walk, and bounce on the slave, giggling all the while at his discomfort.
On their own each girl doesn't weigh a whole lot. But when the three of them together are standing on the slave, he starts to realize that his bones are enduring quite a bit of weight. His hands are tied to his sides so that they don't get in their way, allowing the girls to stand wherever they want. They stand, walk, and bounce on the slave, giggling all the while at his discomfort.