Like her pyrotechnic stage outfits, her humor is saucy and postcard style - all double entendres and faintly inappropriate fart jokes. 'OK, so here's the proof there was never anything going on with me and Robert Pattinson. I fart in front of him. Properly fart. And I never, ever fart in front of a man I am dating. That's a rule.' It's typical Katy - a disarming way to difuse an awkward topic. 'He's my bud. I'm like his big sister. We just hang out. The other day, I said: "One of the things I'm most proud of is not sleeping with you, Robert." And that's true.' Part of my thinks quiet, English Robert might be a lovely boyfriend for Katy. Yet, it's clear, given her predilection for bad, big-mouthed boys, that he is absolutely not her type. (...) She also has A-list girlfriend, with whom relations sometimes seem a little strained. Mortified at being painted as the other woman, she made sure Kristen Stewart knew the Robert Pattinso...