The 'Pure Shores' hitmaker leaves her teenage son red-faced when she performs the band's 1997 hit, which features the line ''you know I want to be a diggy down boy'', but that won't stop her.
In an interview with the I Paper, she said: ''He's like: 'Mum, do you have to perform that song?' I'm like: 'Yeah, we do! Don't come if you don't like it!' But I get it: he's embarrassed. He's 17 years old and I'm his mum.''
And her bandmate Shaznay Lewis reminded her: ''Yeah! And his mum's singing: 'I wanna be diggy down!'''
The 43-year-old singer split from former Oasis star Liam in 2013 after it emerged he'd fathered a child, daughter Gemma, now five, with journalist Liza Ghorbani, and her heartbreak inspired All Saints' 2016 comeback single 'One Strike'.
While Nicole initially found it ''difficult'' to perform such a deeply personal song, she now finds it ''funny''.
She said recently: ''It literally floored me. It was difficult to perform at first. I had to think, 'OK, hold it together'.
''But I don't feel that way about him any more at all, so it's actually quite funny now.''
Despite the previous tension between them, the 'Never Ever' singer is still in contact with the 45-year-old rocker.
Speaking of the 'Wall of Glass' hitmaker - who is also father to 19-year-old Lennon, his son from his first marriage to Patsy Kensit, and Molly, 21, his daughter with former Kill City star Lisa Moorish - she said: ''[We have a son together] so we have to talk. But it feels like a lifetime ago now.''
For the rest of the group - which is completed by Melanie Blatt and Nicole's sister Natalie Appleton - writing 'One Strike' was a natural thing to do because the blonde beauty's heartbreak consumed them all.
Songwriter Shaznay said: ''With 'One Strike', I was so consumed by someone else's situation.
''I didn't purposefully set out to write about someone else's life, it was just feelings.''
Natalie added: ''Nic's life was our life. We were affected by it every day. It was our sister.''
His new album Underneath It All is out now.