Picture: Ella Byworth for Metro. This discovery happened by accident. The researchers were working on studying pain and discomfort during sex, and needed a tool to create pain so they could analyse it. Typically, researchers just use balloons that are gradually inflated, but these often slip out of the vagina midway through the experiment.
Cup and balloon I take a cup from my kitchen, and I go to my mom's room -- when she not there. I then take my pic of Britney Spears. I take a balloon, fill it up most of the way with water. I then place the balloon in the big cup and make sure it's a tight fit. I then rub my dick with lube vegetable oil and shove my cock in the balloon. I then fuck like crazy.