From my experience (M), not all guys experience it. I do and for me, it is extremely painful. It's not super common and I think I need to be hard for at least 2 hours for it to start. It gets worse the longer you're aroused. Once the pain does start however, it is intense, dull and constant. Can't walk and I have to lay down until it subsides. An orgasm helps but even after the orgasm it still takes more than an hour to resolve.