Bye-bye Tee-too

Last night, while playing the time-honored game of peek-a-boo, I heard something that astonished me. When I pulled the blanket back, N clearly called out, "pee-boo!" Pee-boo? Pee-boo? After a moment of surprise, I responded "What? Not 'tee-too'?"

Proud of his newfound eloquence, N grinned, shook his head, and once again vocalized, "Pee-boo!"

Oh, you may laugh at me, or purse your lips in disapproval if you will, but I tried for about 5 minutes to hear my old friend, "Tee-too"... but N would have nothing of it.

Later, I discovered that his tummy has become ticklish.

Who is this child and what happened to my baby?