Same as you guys. My ex wasn't ticklish before an orgasm at all. After going at it and pleasured multiple times, she was quite ticklish but I would only do quick tickles. After mine, she would tickle me and I couldn't do anything to stop her. Quite thankful she had mercy on me haha.
But to better answer your question, you're incredibly sensitive. It's torturous only because it's such an amazing feeling. I'd compare it to a girl focusing on the head, all over your body.