The 35-year-old and Vogue, 29, announced their break-up earlier this year, two-and-a-half years after they tied the knot, but they remain good friends.
Speaking to the Irish Mirror, former Westlife singer Brian said: "If people break up, they break up and it's not as big a deal as people make it out to be.
"Two people can break up and be happy and move on but still have a friendship."
Brian and Vogue are still such good friends that, just two months after they announced their plans to divorce, he's attending her 30th birthday celebrations next week.
He said: "Vogue is brilliant, she is lovely. I'm coming back [to Ireland] next week – I've a couple days off and Vogue turns 30 next week so I will be back for her birthday party.
"It was instant for us. The one thing we didn't want to lose was our friendship. So it's not hard at all."
Brian was previously married to Kerry Katona and they have two daughters together, Molly, 14, and 12-year-old Lily Sue.
On Father's Day this year, Brian took to Twitter to praise Kerry's new husband George Kay for taking on his kids.
Brian wrote: "Happy Father's Day @mrgsjkay thanks for keeping our family together! Your [sic] a great man."