One of my co-worker's wives was an EMT. She told us of call she went on where a guy had a jaw injury. When they asked him what happened, he said "She bucked me" as best as he could. Basically, he was going down on his girlfriend, and she thrusted her pelvis, ramming it into his jaw. Anyway, "she bucked me" became an ongoing joke among our group.

By the way, there was a TV series called "Sex Sent me to the ER". https://www.imdb.com/title/tt3415250/

The show does some re-enactments.

Knockout
 

I've posted this before, but it fits. My GF's parents went on a trip, my GF stayed back because of finals. She was supposed to stay at her BFF's house under supervision of her parents. But, being sly teens the girls told her parents they were going to a mall and a movie, when she was going to meet me at her house to sneak in for some rare privacy. We parked at a nearby store and walked separately to her house so a neighbor would not see us.

As soon as we got inside we went to her room and got into sexy times, I had a pocket full of condoms, just in case. Her favorite was to start was on top of me, she was grinding away, we were both getting into it when the door to her room opened. I couldn't see who it was, but my first reaction was to get up, my GF's first reaction was to dismount, her knee was swinging over just as I sat up and it caught me in the side of the head like a punch. I was out cold.

The person was her aunt, who was asked to water the plants, she heard noises and went up to investigate. While I was unconscious, naked GF and her aunt were trying to revive naked me. I came to with the site of she and her aunt putting ice on the side of my head, I was aware that I was naked and this strange lady was standing over me, and I had a hell of a headache. At this point they put a blanket over me and GF got dressed.

Aunt Nancy, who was attractive, said I had a concussion and had to go to the ER and my parents would have to be called. So they concocted a story that I was hurt on the trampoline, I called my parents to meet me at the ER. Aunt Nancy took me to ER where my parents were waiting, she took GF back to the mall to meet her friends. All tracks covered.

Later Aunt Nancy had a talk with GF, she was pretty cool about it. She said she realized that once young people have sex, that's what they are going to do, but what we did was a stretch. I saw her at Thanksgiving at GF's house, she gave we a little smile, but she never ratted us out.

My wife and I are currently on a two-week break because we found a new position that resulted in an injury to myself!

More details???

After a dozen orgasms and squirting enough to soak the bed, she was "done", so I found a slight change in position that felt amazing to me and didn't bother her too much to keep going. I guess while it felt good, it was a terrible idea, and while I can get hard, I couldn't do anything for about two weeks.

I think I was ramming her at a weird angle or something with "just the tip", causing it to swell up for a week and a half.

It seems back to normal today, though!