The Chocolate Touch by Patrick Skene Catling

"If he could, John Midas would eat nothing but chocolate all the time, and he'd never share it with anyone. Then one day, John finds a strange coin on the sidewalk and uses it to buy a box of chocolate at a mysterious new candy store. Suddenly, everything John's lips touch turns to chocolate! Chocolate toothpaste and chocolate water fountains are great, but things get complicated when John can't play the trumpet or bob for apples. Worst of all, he forgets and kisses his mother! This funny be-careful-what-you-wish-for story has been delighting kids everywhere since it was first published in 1952."--Page Web de l'éditeur.