For someone lazy to search.
Explaination: Peyronie's (pay-roe-NEEZ) disease is a noncancerous condition resulting from fibrous scar tissue that develops on the penis and causes curved, painful erections. Penises vary in shape and size, and having a curved erection isn't necessarily a cause for concern. But Peyronie's disease causes a significant bend or pain in some men.
Simple: Bend Penis and it's painful.
(You can tell me to delete this image if it's against rules.)