You say tomato, I say shitty

I was loading the two kids into the car yesterday when old baby piped up.
"It's shitty outside".
I popped my head up from new baby and his car seat buckles to say "what was that"?
"It's shitty outside mommy".
I looked at him closely and asked him to repeat himself one more time to make sure I'd heard what I thought I heard.
He repeated "It's shitty outside" with this strange little grimace he gets when he's pretty sure he is in trouble for something.
"Honey, who taught you that word"? No answer.
"Honey, who taught you that word?" Nothing.
"Who taught you that word 'shitty'"?
Finally, I realized he was saying "chilly". "Mommy, it's chilly outside".
Of course, now mommy is the one who taught him the word "shitty".
Great, Can't wait for Easter Sunday with the family!