Elliott, 34, allegedly discovered texts on 32-year-old Chloe's phone from rugby player Danny, 27, when they slipped off to a toilet cubicle at the National Television Awards last month.
TOWIE star Elliott is said to have flown into a rage, which ended with him smashing Chloe's phone.
A source told The Sun: "While inside the cubicle, Elliott saw messages to Danny from her phone. He quizzed her about it and it quickly escalated into a very heated argument.
"Weirdly they then went to Libertine nightclub. Elliott was still very angry about it and the night ended with him smashing Chloe's phone."
Elliott and Chloe, who both have children from previous relationships, first split last year, when Chloe discovered he'd shared a bed with another woman.
They reconciled at Christmas, with viewers seeing them make up on The Only Way Is Essexmas, but called it quits again shortly afterwards.
Speaking about their break-up last month, Chloe told OK! magazine: "We got back [together] at a really stressful time of year – it was Christmas and obviously we're both parents so it was quite a difficult time for a new couple.
"It should be really romantic and it wasn't – it was very hectic."