A hand gesture involving mostly the index, middle and ring fingers moving up and down rapidly.
It is similar to a type of handshake.
The idea of "toesies" was brought about by tiddlywinks as well, but that gesture refers to the toes.
Ryan: Tiddlywinks!!! *makes gestures*
Jeremiah: Tiddlies! *makes gestures back*
Dani: Wow...really? Come on, guys. Grow up.