When I wear earrings without backs (eg fish-hooks, elongated drops) one of them will often creep up out of the piercing. Not always the same one. I've lost several earrings this way. Of course I could put a plastic earring-back on, but that can spoil the appearance of the earring, and doing this has bent some of them.
Why? What is it about my earlobes that extracts earrings?