"It was awkward. We hadn't been back in the situation of being together every single day, being on stage, rehearsing, getting ourselves back into Spice Girls mode, and then all the headlines about our relationship were thrown into the mix, which was pretty bad timing."
The 44-year-old star says that because she and her band mates - including Geri, Mel C, and Emma Bunton, as well as Victoria Beckham, who didn't take part in the reunion - have "grown up", the historic tale didn't go down as well as it would have if they were still as "outrageous" as they used to be.
She added: "We have all grown up. Geri and I were always the loud, bossy ones, Mel C and Emma were much quieter, but we've all changed. Mel C is so much more chilled and sorted and knows exactly what she wants, as is Emma.
"Geri is different. She's married, she's got kids, she's not the same outrageous Ginger she used to be. That took a bit of getting used to for me."
But Mel insists she's "changed" too, as after divorcing Stephen Belafonte - whom she accused of being physically and emotionally abusive - she now wants to be "up front" about her life.
Speaking to the Mail on Sunday's Event magazine, she said: "I've changed. I've been through ten years of a deeply abusive marriage. I've lived a lie for a decade and I've come out of it wanting to be so honest and so up front about everything."
When Mel made her confession earlier this year, she insisted the romp would never "happen again", as they realised it wasn't for them.
