When leaving the presence of a girl (usually girlfriend, but any girl you have performed any sexual acts with will suffice), you jab her in the throat and immediately give her a hickey where your punch landed.
I was leaving Jenny's house and I gave her the Manchurian Goodbye on my way out.
When, the morning after, the girl leans forward for a goodbye kiss from her man and he lightly punches her in both eyes, swelling them shut Chinese style.
"He gave his girl a Shanghai Goodbye so everybody would know she was taken."
When someone avoids emotional situations by cutting off all communication and contact with specific people and goes on with life like nothing ever happened.
Rather than be honest about the reasons behind her actions Iranga pulled an IrishGoodbye... again.