Mel joined Tulisa, Gary Barlow and Louis Walsh for the latest round of try outs in Manchester.
Discussing her fellow judges, Mel said: "Louis is lovely. He’s always pranking people backstage. We spent a lot of time teasing him about his hair.
"Gary’s brilliant; he was really serious at first but I livened him up. He’s got a very dry sense of humour, he reminds me of Victoria in that respect."
She added: "I got on like a house on fire with Tulisa. She’s really down to earth and you know where you stand with her. Tulisa also has a very sweet side to her."
Speaking to the official ITV1 website, Mel B also made fun of Gary's bizarre showbiz diet!
She joked: "We had a laugh [backstage]. I’m a northern girl so we’d order in fish and chips. Except Gary, who’ll only eat baby food because of that macrobiotic diet he’s on."
Meanwhile the former Spice Girl joined Mel C in campaigning for a Spice Girls theme week on the live shows this year.
She told the website: "Too right! I would LOVE to see a Spice Girls themed week. My favourite song of ours will always be Wannabe. I would love to see Who Do You Think You are performed on a Live Show."