When handed your change in a badly staffed supermarket chain, the sour faced till staff drops a receipt, a fiver that looks like it has been up his/her arse and then drops the coins uncaringly on top so as you are stuck with a ball of money and the inability to seperate them as your other hand is pre-occupied with your shopping.
"Coins Under Notes Thanks! That way I can keep the metal seperate from the paper just as most wallets allow.You fucking piece of tit shit"
That way you can call them a C.U.N.T. without them knowing! And then punch their fucking teeth out of their sad moon face