What's it called when you put your finger on your lips parallel to them and move it up and down, making noise?

Question

Like in cartoons. They usually made a "b-b-b-b-b" noise, like halfway between a raspberry and a motorboat. Except, again, with your pointer finger on your lips and with your finger parallel to your lips.

Answer 1

Its actually called a face flap...

Answer 2

There really is no set term for it (like the raspberry). People just call it different things. Here are some names that I found:

wabba wabba
dweeberlips
bubba wubba
elderberry
boysenberry
mumble rumble
kazoo kiss
flubber de dub
bagel-facing
flubbering

Answer 3

I go with dweeberlips

Answer 4

I want the answer to this!

Answer 5

MADNESS