I had one of these last year. I initially assumed he'd turn out to be a timewaster just asking endless questions by email and getting off on the fantasy but he was genuine. He started off lying next to the bed so I could sit on the bed and press on his back then his front with my feet, then he lay on the bed and I did the trampling thing while leaning on the wall for balance. His back (avoiding standing directly on his spine or kidneys), stomach and chest could all support my weight (77kg), no problems. As others have said, hold onto something for balance. It seemed easier for him to take my weight when he was lying on the bed. I guess the springiness of the bed absorbed some of the pressure.