THE WRITE STUFF: A grimy east London warehouse party with sticky floors and graffiti doesn’t seem like the natural habitat for the former Spice Girl Geri Halliwell. But that didn’t phase the pop star who was on hand – along with model Liberty Ross – to mark the opening photographer Matt Irwin’s show “Punk. Perfect. Awful,” co-hosted by magazine Dazed & Confused. Halliwell admitted she wasn’t a regular visitor to the trendy neighborhood, but said she’d donned an oversized vintage blazer especially for the occasion. She also lifted the veil on her latest project. “I’m writing, but I can’t say any more,” she said.