I have to assume this implies sexual touching. If I show them a shot on the back of the camera and they ove it so much they give me a hug, I don't sweat it. As a boudoir photographer I have done shoots with lovers and touching was expected and encouraged. If it were just an "off the street" client, I would request they stop. And if they don't I would request they leave. Immediately. We will figure out the business arrangements later, but leave now.