Oops!

For the past few years my family has done a Secret Santa gift exchange for Christmas. We draw names on Thanksgiving and get to spend all our energy on that one lucky person we draw. We don't find out who everyone has until Christmas day, when the presents are exchanged. Well this year I accidentally told my sister who I had! I was casually talking about Christmas shopping and mentioned, "Well since I only have to buy a present for ________" AND ACTUALLY SAID THE NAME! I swear I'm not trying to ruin Christmas...