Once, we were playing football and he was in goal. I took a shot, he stopped it, and somehow it broke his arm.
Second time, we were walking down the stairs. I was behind him and I tripped, fell onto him. We both fell down the stairs, and when we hit the bottom, he broke the same arm again.
Finally, we were playing football again, I went in with a slide tackle, knocked him in the air, and caused him to break the same arm for the third time. (This time it was more my fault than any other.)
It's become a frequent, boring event now. The first time everyone was shocked, now everyone just sighs and groans 'again?'