The iconic war-cry of Australia's most lauded political idiot, Pauline Hanson.
Interviewer: Are you xenophobic?
Hanson: Please explain.
A phrase used by authority when the proverbial s**t has hit the fan/someone has done something really stupid and the responsible party/scapegoat is being called to answer and take liability for their actions (also known as getting a boot up the backside).
There have been reports of abusive language in front of customers, and management has asked for a Please Explain.