What Do You Say When You Tickle A Baby? Is It Goochie Goo Or Coochie Coo?

It's the done thing when a baby is laying on the floor laughing, to go in and tickle their belly and say... well, what do you say?

In this hilarious video, one man asks a 'Slang Historian' (yes, that is a job title) exactly what we should say when we tickle a baby.

He flips between whether it should be 'Goochie, goochie goo' or 'Coochie, coochie coo'.

So, which one is it?