Lisa: So, Dad, were you excited that Mom was pregnant?
Homer: Actually, your mother hadn't told me. At that time I had no
idea Maggie even existed.
[he goes to sit down, right where Maggie is]
Bart+Lisa: Dad! [Marge grabs her away]
Homer: [not realizing] Hi Maggie!
-- At _that_ time?, "And Maggie Makes Three"