Pookie

The act of being a little baby about things, not performing a thing your friend has asked you to do. Or refusing to do a challenge made by a friends. Named after a thing that a mother might call her baby. Term made as a PG version to say a swear.

Guy: Hey, wouldnt it be funny if you jumped off this dock.
Ashton: No, i might get hurt.
Guy: Damnit, Ashton. Your such a pookie.