As the colourful documentary follows the singer on her tour, Brand makes brief appearances, congratulating his then-wife backstage and endearingly calling her sausage.
We see Katy planning relationship days with her manager and assistant, who make no secret of their worries about her schedule, which sees her flying around the world to see Brand for a few days during the tour.
While Katy is shown in tears, she comes across as a private person at heart. Her entourage claim not to know why shes breaking down before a concert in Brazil, although they look like they could hazard a fair guess.
When the singer finally talks to camera about the relationships end, its in general, careful terms, talking about her idealism and commitment which she applies to romance as much as career.
Shed hoped to meet someone who could support her in her fully in her career and hints that this didnt happen. But this is no tell-all, for reasons that may be a mix of personal, professional, political and legal.
Still, Part Of Me is an enjoyable 3D extravaganza that showcases Perrys bubblegum pop tour in all its glory.
As youd expect, its a fashion rainbow of bold wigs, cutesy dresses, slinky catsuits and sparkling adornments although Katy does appear without make up, barely recognisable as shes dragged grumbling out of bed.
Youre left with the impression of a friendly, focused and talented performer, but one whose personal story is only half told.
Katy Perry: Part Of Me 3D is on general release on 5 July