My Son, the Sun

Yesterday, while at the dining table, I reached for the day's copy of The Sun newspaper for Julian to read.

Me (pointing to the logo on the masthead): Julian, what's this?
Julian: The Sun!

Now, The Sun newspaper has "On [the day of the week]" stated just below the logo. So, wanting to test Julian...
Me (pointing to the day of the week): What's this?
Julian: On Monday!
Me: Very good! *beaming*

Angie was close by...
Me: See... that's my son!
Julian: No! The Sun!
Me: ??!??!?!