TOWIE drama: Mario and Lucy call off engagement after cheating row
Lucy - who lives with Mario - had become upset by rumours he had been texting another girl.
She told best friend Lydia Bright: "It's so frustrating, I live with him, the dogs are there I can't go on a break from him. My dad's moved away and I don't have a bedroom there anymore.
"I'm not a stupid little girl, I know it's not right. But he's not physically cheated on me. I need to get out of the flat and give him some time to work out for himself what he's done wrong."
It was revealed on Sunday's episode that Mario had been texting one of Mick Norcross' 'High Street Honeys', despite his promise to 21-year-old Lucy that he'd put his womanising days behind him.
The couple had previously split after Lucy found a string of messages Mario had sent to other women.
So, on last night's episode, Lucy pulled in Lydia's help.
Lydia rang Mario, 24, and told him: "She's very very upset, Mario, as you can imagine. She feels you think she's overreacting.
"She loves you a lot and has asked me to say all this because she finds it hard to talk to you about it.
"She's been through all this before and she feels enough is enough and she has to draw the line.
"What are you going to do about it? I can't sit by and see this happen every month. No matter what the messages said, you shouldn't have been speaking to other girls."
He said: "There's a lot of things that have happened in the past and if I hadn't forgiven her, we wouldn't still be together.
"They were totally different messages to the ones I was sending seven months ago. This time, I was having banter with girls about Arsenal and Tottenham. If it was some fat munter, she wouldn't care."
Lucy eventually agreed to meet Mario, but the situation soon escalated into an argument and she was frustrated he'd passed the messages off as "banter".
She fumed: "Everything is wrong with you bantering a girl when it's about them in a leotard."
Mario replied: "I've said I'm f*cking sorry! The boys don't think I've done anything wrong. Yes I admit I'm in the wrong, but it's not the worst thing in the world."
He also labelled Lydia a "f*cking busy pr*ck".
Mario soon made an effort to patch things up with Lucy, agreeing to cook her dinner - and doing so in the nude.
And the pair mutually decided to call off their engagement.
Mario said: "We were happy before we were engaged. That ring, to me, is a symbol of the bad memories and everything that's happened over the past few months."
Lucy agreed: "We're getting rid of the ring. It will feel weird without it, though."
Mario asked Lucy to marry him on an episode of The Only Way Is Marbs this summer.