The Edge's Sharyn Casey busts listener's cheating boyfriend in shocking phone call on-air

Host of The Edge radio's afternoon show Sharyn Casey busted a listener's cheating boyfriend in an elaborate ruse that took place on air. 

An anonymous woman called in the station to request Casey and her co-host Jayden King's help in catching out her partner of five years, who she suspected of being unfaithful. 

Casey then called the man - who's identity was also kept secret - and pretended to be a friend of the woman he was allegedly having an affair with. 

Casey said she was attempting to throw a surprise birthday party for the 'other woman' and asked the man if he could help get her to the event. 

"You could see if she wanted to go on a date, you guys could go for dinner somewhere and then you could bring her up about 8pm?" Casey asked. 

"You guys are official boyfriend and girlfriend now right, so it wouldn't be weird if you take her on a date?"  

The obviously nervous man replied that the relationship was "pretty fresh" but that he didn't think it would be weird for them to go on date.

"Have I confused things?" Casey asked. "Are you guys just friends or are you dating? Sorry, oh my God, I should have checked, I thought she said you guys were dating." 

"Oh, um yeah, nah, yeah, I guess you could say we are…" the man replied. "I guess we're mates but it's a bit more serious than that."  

"You're the guy that she's been hooking up with for a few months?" Casey confirmed. 

"Ah...yeah," said the man. 

Having double and triple-checked that the man was definitely involved in some kind of infidelity, Casey delivered the final blow, while her co-host King looked on in horror. 

"Just one other question I had: When you ask her out on the date, will you put that in your calendar, and will you also put it in your girlfriend [name redacted]'s calendar?" 

"Um, oh, okay," the man stammered. 

"I just know that you and [girlfirend's name] have been together for five years, so just wondering if she likes to keep up with your other relationships," Casey pressed. 

"Yeah look, I think I'll leave you to it eh? Yeah. Seeya," the man finished, at which point Casey and King reconnected with his tearful girlfriend, who had been listening to the entire call. 

"I'm so sorry," Casey told the girlfriend. 

"It's okay, oh my God," the sobbing woman replied. 

"I knew that it was probably real, but it's kind of f**ked up when you hear it. I really appreciate you guys doing that - it was actually very clever," the woman said. 

A visibly upset Casey had some parting words of wisdom for the listener, telling the woman she too had experienced being cheated on. 

"From someone who has been in your shoes before, I just want you to know that right now it feels really crap and it feels embarrassing and you feel like you've done something wrong," she said. 

"I just want you to know you have done absolutely nothing wrong - this is all on him, it's not on anybody but him. He is the one that made a mistake, there is nothing wrong with you, and please don't let this stop you from meeting someone who really deserves your heart."