Have you ever accidentally hurt your S/O during sex!?

Last night my S/O and I thought we had the green light to do the deed as he told my 15 y/o step daughter we were going to bed and usually after that she doesn’t bug us. Well a few minutes in to him going down on me there’s a knock at the door! We both went to jump up and I kicked the crap out of the side of his head by accident. He has head issues due to a car accident a few years back and was in awful pain. I felt so bad and kept asking if there was anything I could do and apologizing. By far the worst thing to happen during sex this far! Have any of you ladies accidentally hurt your S/O during sex and care to share your story?