Um...as a dude, I can't say that's supposed to hurt. You might wanna go get that checked out. Sure, it can make a mess, but I don't know why it would hurt.
@Empshok, can confirm, think you might have a problem there op
@Empshok, maybe he's referring to the pain of cleaning your pee off of the wall
@Empshok, second that
@Empshok, I think the picture is referring more to how much more difficult it is to pee with an erection rather than a flaccid penis.
Apparently mothers who have had kidney stones say that the stones are worse
@Jakobian, Men get them more often and have to pass them more often
Um... That doesn't hurt dude... Go see a doctor