Here is the best try not to laugh or grin (cartoon edition) challenge. Just Try not to laugh smile or grin and you will win this.! If you enjoy the video dont forget to .\rbr\rbrHere is the best Try Not to Laugh or Grin Challenge. Just Try not to laugh smile or grin and you will win this. If you enjoy the video dont forget to press like button .\rbr\rbrHope you all enjoy this try not to laugh or grin while watching this challenge! This try not to laugh challenge is the hardest challenge on youtube, and is .