The practice of tying a handkerchief around a lady friend's neck before ejaculating on her face. The handkerchief protects any clothing or jewelry the girl may be wearing, while still allowing the man to enjoy pornographically decorating his date's face and hair.
The name originates from the common technique of wrapping a napkin or towel around the neck of a bottle of wine to prevent liquid from dripping onto the table. The "Chilean" part refers to the delicious, yet relatively inexpensive wines of Chile, and serves the dual purpose of just sounding dirty.
That girl from the party was blowing me in the closet, and didn't want to get my load on her cocktail dress, so I whipped out a hanky and gave her a Chilean Necktie. Didn't do much for her mascara, unfortunately.