I finally caught Chase mimicking me when I sneeze today. I thought he had been doing it some mornings in the car (I drive into the sun when I take him to school and bright sun makes me sneeze!).
Well this afternoon he was eating a snack in his chair and I was sitting on the couch. I had two monster sneezes and when I recover, I look over at Chase and he is throwing his head forward saying "aa-choo" with a big smile! We then milked it from him a few more times! So precious!!