Madonna made a backing dancer kiss her feet.
One of the 'Rebel Heart' hitmaker's crew turned up late to rehearsal and she is such a "perfectionist" and stickler for timekeeping that she reportedly ordered him to apologise in the unusual fashion.
A source said: "The dancer was only a few minutes late and apologising like crazy."
And the insider also revealed the procedures that take place before the 57-year-old singer reaches a venue for soundcheck.
They told the New York Daily News' Confidenti@l column: "They know she she's coming because they radio ahead. The first thing that happens is that [organisers] throw out all the water bottles because she can't stand seeing half-empty bottles.
"Then they dim the lights and light candles because she likes the room to look and smell a certain way."
Meanwhile, the 'Living for Love' singer recently took to Twitter to thank her fans as she wrapped up the first night of her 'Rebel Heart' tour.
She wrote: "Thanks to all my Rebel Heart Fans! I felt your love! #rebelhearttour. This Unapologetic Bitch loves you Montreal! #rebelhearttour.
"Music makes the people come together! YEAH!!! Opening Night #rebelhearttour... Montreal (sic)"