Madonna performs on stage during her concert at Olympic stadium in Rome on June 12, 2012. Credit: EPA/CLAUDIO PERI/LANDOV

She's not sorry, indeed!

In Rome on Tuesday, during the latest stop for her MDNA tour, Madonna gave concertgoers a glimpse of something special -- nearly mooning the audience in barely-there skivvies.

Days after exposing her nipple to fans in Istanbul -- outraging some -- during her song "Human Nature," the 53-year-old pop legend and mother of four pulled a similar stunt during the same number in Italy.

Clad in a sexy lace bra and trousers, with her blonde locks swept up in a dramatic retro 'do, the Grammy winner yanked down her black pants, revealing her posterior in a lacy, G-string bottom. (Appropriately enough, the 1995 song "Human Nature" is all about Madonna's unapologetic stance for her explicit, edgy Erotica album and Sex book of the early '90s.)

The icon was criticized in some corners for showing her breast in Istanbul last week during the striptease routine. "What works for a 22-year-old woman or a man is not appropriate, very often, for a 53-year-old," Donny Deutsch complained on TODAY recently. At his, Dr. Nancy Snyderman sniffed. "Not special," she said. "Not a special breast, not worth doing."