Sunday night's episode of Married At First Sight showed fan favourite Cathy opening up about her cheating-riddled love life, and how she fears new husband Josh will break her heart.
And now, she's spilled the exact moment her trust in lovers was shattered.
MUST WATCH: MEET MARRIED AT FIRST SIGHT 2020'S CATHY
Chatting to 9Now, Cathy said her last brush with cheating happened two years ago - and it was rough.
'I found out by the girl sending me a message on Instagram saying, "I didn't realise you two were in a relationship because your ex has told me that he was single and we'd met on Tinder," and they'd been seeing each other for two months.'
And bizarrely, the philanderer was preparing to propose to Cathy!
'In those two months he was telling me to look for what kind kind of rings I liked because he was going to propose. So for me, I was really set that "oh I've found the one."'
It didn't take Cathy long to pack her bags and leave. She says she confronted her ex the same day she moved out.
'I didn't know whether to cry or scream,' she says of learning about his dog act.
'I was an absolute wreck, like I felt broken, like how could someone really destroy my trust like that? I'll never forget it.
'I think that really taught me what love can do to you, like I put my heart in his hands and he quite literally crumpled it like paper.'