Cracker Jokes and Rainbows

I love christmas crackers and the jokes this year weren't too bad. Did you know that cracker jokes can be as controversial as Brussel Sprouts (YUM). Well that's what the BBC says in their article: What Makes a Good Christmas Cracker Joke? Here is one I think is worthy of a slight happy groan.
What bow can't be untied? answer below


Rainbow in Puerto Rico Dec 2009