Strap-ons are serious business. I didn't appreciate it at the time, but I've learned my lesson with long term consequences. My girlfriend and I at the time of the incident were relatively experimental and kinky, but too young and inexperienced to practice safe, sane sex. We purchased a medium sized strap on for her to try on me, since I had expressed some desire to experiment with that. We had already developed a liking for bondage and gagging and in a rather ill-advised fit of compulsiveness / passion decided our first night with the strap on those elements included. She tied my up face down, ass up on the bed and tied the ball gag around my mouth. She entered me slowly and with a significant degree of lube and so at first it was fine and exciting. After a fairly short period of time, I think the lube started to congeal slightly and it became somewhat painful at first, and then extremely painful. I called out for her to stop, but I had been moaning in such pleasure and the ball gag kept me from uttering our safeword (which we rarely used anyway) so she mistook the pain for pleasure and started thrusting harder and faster. The grew obviously intense suddenly and I screamed. She mistook this for some kind of prostate-induced orgasm and began thrusting as hard as she could. I was in excruciating pain, obviously, but I was terrified because at some point the dildo started easing its way back and for quite smoothly. I knew she hadn't applied more lube because her hands were around my neck, and no amount of spit could have produced this result. It turned out that an artery in my colon had torn and was literally filling my intestines with blood. It spraying out and soaking the sheets. At some point she realized it and screamed in horror. When she pulled out the torn inner lining of my rectum sort of "exploded" out in a prolapse, which splurts of blood sort of spraying out all over her. There was also some loose stool that came out, so we found out after I returned from the hospital 2 days later with 75 internal stitches, 3 subsequent surgeries, and what would become a lifetime of extreme, frequently tearing hemorrhoids. So it is with no small measure of seriousness that I want clearly and with absolute clarity explain to readers how very dangerous it is to experiment with strap-ons without clear and bullet-proof pre-determined arrangements and safeguards. On top of that, my girlfriend had an emotional breakdown for not only causing me life-threatening injuries, and not only being sprayed with stool-contaminated rectal blood, but also being interrogated by police on suspicion of committing a violent sex crime, as was the policy in a situation with sexual injuries where the victim has rope burns on his hands and legs (I was in surgery for several hours so couldn't explain the situation). We could not continue our relationship the emotional and physical damage was so bad. For those of you who don't believe me and think this is some kind of sick joke (I wouldn't blame you, Reddit is a sick place)here is a pic of the room that night.