A variation of the popular smile face ":)" stemming from a common mistake. Primarily used by mentally disabled children, this emoticon denotes an ignorant sense of joy, or a moment of stupid bliss.
"omgarsh the guy i like likes me back. we might even like hold hands or something pretty soon. ::) ::) ::) ::) ::)"
an alien face DUH!!!!!!!
Person 1: ::)
Person 2: sick with it!