Blowing Raspberries

We like to play a game at our house called "Truth or Dare Jenga". It's just like the traditional Jenga block game, only each block has a "truth" or "dare" written on it. When you pull a block out of the tower, you read what's written on the block, and either answer the question or complete the dare. This morning, I was upstairs taking care of the baby while my three sons were playing "Truth or Dare Jenga". After a few minutes of playing, Brock ran upstairs to find me and exclaimed, "Mom! You'll never guess what was written on the block!!! It said 'blow a raspberry on someone's stomach!' Where on earth am I going to find a raspberry?! Can I just blow an apple instead?"