What's Your Name Again?

One of my students has a baby sister named Isabelle. She always comes along when he gets picked up/dropped off at school.
She, of course, was there this morning when the kids were getting picked up and we all said , "Hi Isabelle!"
One little guy who just loves her, says to his little friend, "Look, it's Isabelle!"
Well his little friend got VERY upset and started raising his voice and getting quite angry. He even hit him!
So I got down and asked him what was wrong, why was he upset.
"She's a baby! She's a baby!" He yelled.
"You're right, she is a baby. Her name is Isabelle."
"NO! She's not a bell! She's a BABY!"

He thought we were saying she is-a-bell.
Love it!