I don't understand this joke - explain?

Frappe frappe.

Qui est la?


...Loste qui?



he's knocking on the door because he lost his key (loste qui)


loste qui? sounds like "lost key". Oui - yes!

they lost their key so they have to knock on the door!


don't worry, I don't understand it either...AND I speak French semi-fluently!


Why don't you get that? It's hilarious!


I think it's supposed to go

Frappe frappe. Qui est la? Liste. Liste oui? Oui!


Looks like a knock knock joke to me


Knock knock. Who's there? Loste. ... Loste who? Yes


me niether