Dannii, 39, also said she was sure Ethan will one day cringe at the revelations in her new autobiography.
She also said she rejected parenting advice from her brother, such as how to change a nappy, before Ethan was born, preferring to wait until "she absolutely had to".
In fact, her boyfriend Kris Smith changed all of Ethan's nappies after he was born, she revealed.
The X-Factor judge made the admissions by phone from London to a radio station in her native Australia.
She said, "Kids think anything their parents do is embarrassing.
"I'm sure he's going to hate it all and everything else that I do."