Why the hell was my man bleeding??!?

My boyfriend and I were getting frisky yesterday. We were kissing and feeling each other. He wanted to take things a step further and he put my hand into his pants. I took him out and did one stroke while kissing. But then he jumped in agony. I looked so confused and worried. I always do this and nothing serious ever happens. He said, "I did it too hard"... But I stood confused because I always do it the same way. He was shaking. There was blood all over him and all over me. I decided to cut the date short in order for his health. I told him to examine where he was bleeding from. And that he needs to go to the hospital. When he got home he took a shower and told me that I ripped the hole of his penis... How the hell did I do that now?... And not any other time... It just doesn't add up... God, I feel so bad.