Sparks flew when Katy Perry joined Madonna onstage on the latest stop on her Rebel Heart tour in Los Angeles this week, as the two pop titans performed together and got rather close with a few raunchy dance moves.

It’s fair to say that 31 year old Perry brought out her inner fan-girl as Madonna invited her to the stage at The Forum in Inglewood, L.A. on Tuesday evening (October 27th). They joined forces for a rendition of Madge’s ‘Unapologetic B****’, and got rather intimate with their twerking, dipping their butts low and grinding at one point.

Best Unapologetic bitch ever! Thank you Katy! Thank you L.A. ❤️#rebelhearttour

A photo posted by Madonna (@madonna) on

Amusingly, 57 year old Madonna and Perry played along to what appeared to be a scripted bit, where the queen of pop treated Katy like a fan, asking her name and giving her a gift of a banana flask. “I’m sure you can find other things to do with this,” she said suggestively, before adding “Bye, bye, Katheryn,” as Perry exited the stage after the song.

More: Madonna kicks off her new tour in rebel style

Later in the evening, Perry took to Instagram to talk about the craziness of the situation, also explaining why she called Madonna “mom” at one point during their exchange. Apparently, all superfans describe their idols this way - “Because all popstars are code ’mom’ #meta,” she wrote.

Madonna later reciprocated the tribute with a message of her own. “Best Unapologetic B**** ever! Thank you Katy! Thank you L.A.” she wrote later that night.

Having released her latest album Rebel Heart earlier in 2015, Madonna is embarking on an extensive world tour, and appears to be taking a leaf out of Taylor Swift’s book in bringing out an audience member each night to help her perform the same song. Previous nights in the tour have seen Amy Schumer and Anderson Cooper brought out onstage.

More: Katy Perry groped by fan onstage in Brazil