In 2003, Guy auditioned for the inaugural season of Australian Idol (which he went on to win), catapulting him into stardom.
Whilst Guy rode the wave of his Australian Idol victory, he and Jules did long distance for two years as Guy moved from his hometown of Adelaide to Sydney to focus on his music career. Eventually, Jules joined him.
"I ended up moving to Sydney, and that was probably when I had to navigate a bit more of the normal day-to-day in the life of Guy Sebastian, I suppose, and just figuring that out," Jules said.
But it wasn't always smooth sailing for the pair, Guy admitting in a September 2023 interview with Sunrise that he and Jules had "secretly split" prior to Guy rising to fame on Australian Idol and that Jules had broken his heart.
"I didn't think we would get back together. I was 18 when we first got together and I think she was 21 (when we broke up) and she kind of broke my heart," Guy revealed to Sunrise hosts Natalie Barr and Matt Shirvington.
"She broke up with me and then Idol happened and I moved to Sydney. But you live life and then you realise, 'Oh, my gosh, I had so much history, she always loved me for me. She's always been the same."
The singer then revealed that he was the only boyfriend his wife had ever had: "I think she's very loving, very smart and emotionally intelligent and so there's so much that I lack where...I might blow up over something and it's always Jules who is my calming force that will help me see things a bit more clearly."
"And me, her as well. I think we balance each other out well. I love her more now than ever so it's amazing."
After eight blissful years of dating, the couple tied the knot in Manly in 2008 before setting off on a romantic European honeymoon.
In May 2023, the couple celebrated an incredible 15 years of marriage, and 23 years together.
"Married to the best person I know for 15 years today," Jules captioned a sweet throwback snap of her and Guy on their wedding day.
In an exclusive interview with our sister publication Now to Love, Jules called motherhood a "life-changing experience."
"When you have a baby, everything changes at that moment, and all of a sudden you just become fiercely protective of this little person."
"Motherhood means so many things because it is literally every waking minute of your day you are thinking about somebody else, it's just how you are as a mum, so you just do it."
Speaking with our other sister publication WHO, Guy revealed that Jules had taken to parenting like a pro.
"I think you have a newfound love for your partner when you see them in a role like that - nurturing and looking after the people that matter most to you. She's killing it!"
But it hasn't always been smooth sailing for the couple, Guy revealing that Jules had actually dumped him in the early stages of their relationship for being a "bad boyfriend."
"She left me before. I was a rubbish boyfriend and I was never there...I was not a gentleman. I didn't believe in opening doors," Guy told the Kyle and Jackie O show in 2017.
"It took her breaking up with me for me to realise I was being a douche," he added.
Speaking with Now to Love, Jules has also previously admitted that "it can't be all rainbows and unicorns every day."