You are going to break your dick one of these days, then you'll be sorry.
http://en.wikipedia.org/wiki/Penile_fracture
Penile fracture is rupture of one or both of the tunica albuginea, the fibrous coverings that envelop the penis's corpora cavernosa. It is caused by rapid blunt force to an erect penis, usually during vaginal intercourse or aggressive masturbation.[1] It sometimes also involves partial or complete rupture of the urethra or injury to the dorsal nerves, veins and arteries.[2]