The former All Saints singer's marriage to Beady Eye frontman, Liam, was rocked earlier this year by the revelation he fathered a secret love child with US journalist Lisa Ghorbani.
Williams, who was engaged to Nicole in 1998, has defended his former flame, insisting she's a very decent person and deserves better, reported Contactmusic.
"I have a very big soft spot for Nic because she's a very decent person. I feel sorry for her as she deserves to be in a good place, in a happy marriage, and I thought she was with Liam. But it would appear that they weren't," Willaims said.
The 39-year-old singer is now happily married to Ayda Field and has a 13-month-old daughter, Theodora Rose, with the actress.