From 'AUNT' to 'ANUT' then ended to 'ALIEN'

I found often that every time I almost lost my patience when accompany Ian to learn how to spell or write, there's something funny happened and made me laugh. His innocent made this happened. Our main purpose would substitute with something else.
This was our conversation this Saturday morning when we were learning how to make a family tree picture and write down the words under every picture. He always write 'aunt' with mistake spelling 'anut'.

Me: "Ian...gosh, how come you write this 'anut' over and over again? The right spelling is A-U-N-T, Ian...."
Ian: (silent)
Me: "You know what, if you write like that it will sound like an alien's name..."

I tried to make a joke, so he won't be sad or at least want to write again.

Ian: "Hah? Alien? Really, is there an alien who have name like that?"
He became curious with his 'funny' facial expression.
Well, you can guess.. after that we won't talk again about the "AUNT" thing, but "ALIEN".
Wrong strategy from me, haha...maybe that's why he can't spelling other words either.
Often our 'talking' spread everywhere, but it's fun and we enjoy it. Ah, forget about "AUNT".