Emotional lateralization Puns

So I was waiting in the car while my parents were waving off my sister to go on a school trip.

I’m on my phone, chilling out when I suddenly see a girl of about 4 or 5 with her mother walking past. They are talking but all I catch is the little girl saying:

“The wedding was so emotional, even the cake was crying!”

I found this hilarious, and later passed it on to my father who then said

“If the little girl wanted to be smart, she should of said ‘the cake was in tears’” (as in tiers of a cake)

I just face palmed at this moment 🤦🏻‍♀️

"Thank you all for joining us tonight, it's been a very emotional evening for all of us, even the cake is in tiers."

I didn't get it until later.