When my niece, Riley, was about a year old, she started calling Ethan "Bo Bo". She could say Ethan and we have no idea where she got Bo Bo from. But, she called him that for a long time. Luke eventually started calling him that. I remember one day, he said to someone, "This is my brother. His name is Bo Bo." If anyone else ever tried to call him that, he let them know very quickly that he was the only one who could do that! It was so sweet. They fight and argue, but they love each other so much. They are best buddies. Welll, last week, Luke start calling him "Efan". Now, he doesn't say Bo Bo at all. We asked him why last night and he jus says he doesn't do that anymore. So...no more Bo Bo.