D-A-D spells “Dad”
This morning I was in the kitchen preparing for lunch, and Leo was drawing on his whiteboard out in the dining area. Suddenly he announced “D-A-D spells ‘Dad’!” I looked up and saw him holding his green marker, with a big grin on his face. So I walked out, looked at the board, and saw this:

Needless to say it brought a big grin to my face as well.