The pair came to London as part of a promotional tour and BJS took the opportunity to make his presence felt.
At the time, Saunders held the WBO middleweight title, with Canelo and Golovkin set to fight for the other three.
GGG owned the WBA and IBF belts, while also picking up the WBC crown after Canelo decided to vacate it in 2016.
Billy Joe made this his first question, asking the Mexican why he decided to drop the belt rather than defend it against Golovkin a year earlier.
When Canelo answered in Spanish, Saunders interrupted the translator and said: “I’ll translate that, ‘I s*** myself.’”
The Brit then asked: “Will the winner entertain me, for the WBO 160lbs [title]?
“Golovkin, I was supposed to fight you but talks broke down between me and your team.”
GGG replied: “I know you like to talk too much. You’re a boxer, you’re not a promoter, please.
“If you want, Tom [Loeffler] is my promoter, he’ll tell you.”
Saunders concluded: “Yes, well I’m very, very interested in that fight, love the fight.
“My bit was signed to fight you, but for some reason you lost your pen.
“So hopefully if Canelo fights you – and I think that Canelo will beat you – I’m hoping to fight you or Canelo in America.
“But good luck to both men and have a good fight.”
Now, Saunders will face Canelo on May 8 and attempt to do what no man since Floyd Mayweather in 2013 – beat Canelo.