And now it seems the tables have turned, with Melbourne radio duo Fitzy & Wippa orchestrating what must be the most awkward car ride of all time.
Where do we begin?
The glorious set-up involved Michael Wipfli (Wippa) feeding lines to Guy’s driver Mohammed, and it wasn’t long before things became very, very awkward.
"Your task today is to repeat everything I saw into your ear, okay?" the hilarious video begins, before Guy hops into the car and Mohammed proceeds to say super cringeworthy things like "you're Stan Walker!" and "I've got two wives and six kids".
After the singer had to establish that he was, in fact, Guy Sebastian and not Stan Walker, there was also a deplorable rendition of Bohemian Rhapsody that sounded more like a cat crying.
You can watch the entire video of Guy Sebastian being pranked below. (Post continues...)
We'd feel more sympathy for the dad-of-two, if it wasn't for the killer prank he pulled on X-Factor host Jason Dundas on the Hamish and Andy show in October.
"Dude. Um. Dude something happened with me and Iggy which was really random," the 35-year-old, who is married to wife Jules, told his colleague on air.
"[It was] the last round of the auditions, because we all went out and then it was just me and Iggy in the lift and no joke she leaned in and like, went for a kiss.
"We had a bit of a pash, so it's sort of weird. Bro, please don't say anything, I can't have it get out."
Jason was so appalled, we wouldn't be surprised if his face still looks like he's sucked on a lemon.
What's your favourite celebrity prank of 2016?