Darius on being a Big Brother

Well, when I first told Darius that he was going to be a big brother, and that I had a baby in my tummy, he didn't quite understand. His hand was on my tummy, and he looked up at me and said "I'm too little to be a big brother"
Today, whilst grocery shopping, this Credit Card woman approaches us and sucks us when. When She asks who's going to sign, both Darius and I answered "I will" at the same time. She looked at him and smiled and said she thought he was still too little to sign as she walked over to me. He replied "I'm not little, I'm a big brother!"