I hurt my husband during !!! I feel terrible am I the only one?

Last night we were having and I was on top, being his cowgirl. I reached behind me and grabbed his well lets just say his Jewles and I grabbed them too hard. He let out a yell of pain. We had to stop, I think it made him mad. He was a trooper though and finished later. This morning he was in a lot of pain in that area. I felt terrible, I didn't mean to hurt him. Am I the only one this dumb?