In this version of "immature" you use your "pinkie." Hold your
extended pinkie off to one side of your nose. Move your hand sideways brushing
your pinkie past
your nose. Use a double movement.
Note: you don't actually have to "touch" the nose.
IMMATURE: Version 2:
There is another version of immature
that holds an "i" against your non-dominant palm and slides the "i" downward a
couple of inches while changing the "i" into an "M"-handshape.