Madonna thanked Jessica Chastain for being a "very good bitch" during her gig in Prague on Saturday (07.11.15).
The 38-year-old actress joined the 'Frozen' singer on stage on her 'Rebel Heart' tour during a performance of 'Unapologetic Bitch' at the weekend.
The two women walked down the stage holding hands before the 'Zero Dark Thirty' actress showed off her impressive dance moves before spanking the singer as she crawled on the floor underneath her.
After the song was over, Madonna told her special guest: "You were a very good bitch."
Jessica was thrilled to make a brief appearance on stage alongside the "queen".
She wrote on Facebook: "I gave Madonna a spanking & Ive a video to prove it (sic)"
And alongside a picture of her on stage, she added: "The moment right before @madonna handed me a banana. The fkn QUEEN.(sic)"
So far on her 'Rebel Heart' tour, Madonna has also been joined on stage by the likes of comic Amy Schumer and singer Katy Perry.
However, Jessica is the only guest who got to spank the 57-year-old singer, as she has previously been the one giving out the spankings.