When the tutorial has been completed, you will be asked if you would like to connect to Facebook. You can either connect now, or hit the X at the top of the message prompt. 

If you decide later that you would like to merge your Guest game with Facebook, you can do so from the in game options menu (the gear symbol). When you select the “Connect” button, you will be asked if you would like to “merge” your game with Facebook or “never”. 
If you select “never”, a fresh game will be started on Facebook and your Guest game will remain separate. If you want to enter your separate Guest game again, simply hit the LOG OUT button and select "Guest".

If you want to merge your Guest account with Facebook although you already created a Facebook game, we would have to delete your Facebook game. This way your Facebook account will be free to link your Guest game to it. In this case, please contact us with your request and the support key of the Facebook game to be deleted.