I believe I have mentioned that Thomas so often says 'Dana, I mean Mommy' that I addressed a gift to him from me that way as a joke. I think it's cute, and genetic. I go through all my brother's names before I get to the one I want. So does my mother. And she has been heard to go through all her SISTERS' names trying to find mine. :O So, he comes by it naturally, and I just can't take offense.
But this. This was too cute. Thomas was trying to get his dad's attention and said "Tim, I mean Dad." (Tim is one of his teachers, in case you are curious.)