Jules Neale has revealed devastating details about the betrayal that ended her marriage, claiming her ex-husband Lachie Neale carried on a secret four-month affair with her best friend.

In an explosive tell-all interview on Pretty Sure podcast, the Perth mother-of-two revealed she initially walked away from her marriage believing the betrayal amounted to just a kiss.

However, after packing up her life and returning home to WA, Ms Neale discovered the full extent of the infidelity.

“I guess it was an ongoing, four-month affair with my best friend, behind my back,” she told podcast host Adelle Petropoulos.

“I actually didn’t find out about that until I moved back to Perth.

“I was told it was a kiss and that’s all it was.

“I actually packed up and left because of that and then when I got to Perth, it all came out and I found out that it was a lot more than that, and it had been going on for a lot longer.”

She said being in WA when she discovered the extent of the affair may have been for the best.

“It was probably a good thing that I was interstate when I found out that had happened because it wouldn’t have been good if I was in the same town.”

Ms Neale claims it was the deception surrounding the affair that had been particularly difficult to process.

“The worst part of it is not even the cheating, It’s the lying after the lie. You question your whole reality after that,” she said.

Asked whether she had noticed any red flags while the affair was happening, she said: “I was going back over the last four months of interactions and conversations and being like ‘Oh, I’m such an idiot’.”

The high-profile couple’s marriage breakdown exploded into the public eye in December after Ms Neale rejected reports the pair were “working through” relationship issues and declared she had been “betrayed in the most unimaginable way”.

Her former best friend Tess Crosley was subsequently linked to the scandal after a screenshot emerged of Ms Neale demanding she remove social media pictures featuring Lachie.

Lachie confirmed the separation in January and stepped down as Brisbane Lions co-captain, admitting he had “let my family down” and apologised for his actions.