When Hugh Grant's character gets an earing with his friend, they pierce his left ear. (or his right.I don't remember.) It then procedes to jump ears from time to time until his girlfriend(soon to be wife) asks him to take it out when she is in the hospital.
I don't think it does either. I thought that I noticed something wrong about it, but then I looked closer, and you see a reflection in the mirror when he first gets it pierced. The earring doesn't switch from ear to ear, but it looks that way cause of the mirror image.