rug burns.
my arch had a cramp once.
injuries to who I was having sex with (aka the victims):
I dated this hot clumsy girl and one time while walking to my bed she stumbled and hit her head on the bed frame. She had a big knot on her head but we still ended up having sex.
One time I was banging this chick and I accidently thrust real hard but my dick went violently into her "bad place" (aka balloon knot). She screamed in pain, and I consoled her by telling her to "walk it off". We ended up having having sex shortly afterwards.