Never mind Taylor Swift — it sounds like there's some "Bad Blood" brewing between Katy Perry and her ex-husband Russell Brand.A trailer for Brand's new documentary, Brand: A Second Coming, shows the British comic slamming his ex-wife's celebrity lifestyle. He married the pop star in 2010, but the couple split just 14 months later. Perry has claimed Brand ended the marriage over a text message.Brand doesn't mince words when speaking about his way of life while married to Perry."Oh my fucking god," he says in the trailer. "I’m living this life of the very thing I detest. Vapid, vacuous celebrity. Fame, power, and money is bullshit.""That's the very sea we're swimming in," he added in a quote shared by the Daily Mail . "'Oh, who's he?'...'He's married to Katy Perry.'"Way harsh. Now, these quotes may be out of context. Brand is certainly not the first person to insult an ex. Still, it's worth remembering that he was famous well before he met Katy Perry. He's the one who describes himself as "the second Jesus." He's the one who tried to stage a revolution in British politics by urging people to not vote before doing an about-face and throwing his support behind Labour head Ed Miliband, who then went on to suffer a hugely embarrassing loss. Glass houses, Russell.Watch the trailer below and say a silent prayer that your ex isn't famous and indiscreet.