Mistresses Nancy, Gia, Emily and Kourtney wanted to trample and humiliate a slave together. So they got one and then with their sweaty and stinky feet, trampled his face making it hard for him to even breathe. And they were not doing it in turns. They did all this together so as to increase the slave's discomfort and enjoy themselves at his expense. The slave could do nothing but endure it all.