The joke was on Kyle Sandilands on Wednesday morning when Guy Sebastian pranked the shock jock with an epic skit.
Donning a fat suit, the 35-year-old singer dressed up as an overweight Southern American man for the KIIS FM Kyle and Jackie O show segment called "Should I stay or go?", and Kyle bought every bit of it, till the very end.
In character as Jo Tucker, one of the personalities featuring in his latest Mind On You music video, Guy's port belly could be seen beneath a white singlet and flannel shirt, teamed with a bandana and reflective sunglasses.
After saying he'd been doing a long-distance relationship with his girlfriend, Guy started talking about weight, which really captured Kyle's attention.
"I put on a little bit of weight. I was always fat," he said in a Southern accent.
"Not a lot, maybe 20-30kg," he then added, when asked about his weight gain.
Kyle chuckled, before saying: "I feel your pain, brother".
At this point, Guy was only warming up with his prank, and kept adding more layers to his fake story.
"She's kind of left me with an ultimatum; lose the weight or hit the road," he said.
"Kyle you're a fat guy, and I mean no disrespect. Just like Imogen saying to you, 'I'm not going to date you anymore because you've put on some weight'. I'm the same guy, I feel like she's kind of fat-shaming me and I don't know what to do."
At this point, Kyle had a confused expression, and Jackie said to her co-host: "Kyle, you're looking kind of suspicious".
"Something's off here," the shock jock responded, only leading to Jackie and Guy bursting into fits of laughter.
Guy then decided to come clean, taking off his sunglasses to reveal his true identity.
"Are you kidding? F*** off!" a shocked Kyle exclaimed, leaning back and covering his mouth with his hands.
"Are you kidding? Oh my god, it's Guy Sebastian!
"This is more off than I thought!"