Yesterday, Anthony Joshua caused a bit of a stir on social media, tweeting to former world heavyweight champion Tyson Fury to “get fit you fat fuck,” while also addressing other potential opponents like Deontay Wilder and Joseph Parker.

Fury is not one to let a rival’s trash talk go by without a response, of course, so he pretty quickly fired back.

From Fury’s Instagram:

“To be honest with you, me old mate, I don’t need to get fit for somebody like you at all. I’ll come to you and I’ll punch all your face right in for you, even at 25 stone. So I really don’t need to get fit for you, anyway, put it that way. I’ve seen what you’re about. Useless. No gas, no stamina, too many weights. You wanna practice a bit more speed and less power.”

Fury, 29, hasn’t fought since his November 2015 win over Wladimir Klitschko, and at this point has lost his British boxing license and been stripped of all of his title belts — he gained the IBF (which Joshua now holds), WBA, and WBO titles with the victory over Wladimir. There has been talk of him returning to the ring this year, but none of it panned out, and in public appearances, he’s been well out of ring shape.

That said, it has to be repeated that Joshua vs Fury is easily the biggest money fight possible in the heavyweight division, something that would surely sell a mass amount of tickets at Wembley Stadium and be a huge pay-per-view event in the UK, not to mention demanding major money for U.S. TV rights if it weren’t also a pay-per-view here.

And that’s the reason for the back-and-forth. If the fight ever becomes a reality, it’s going to be massive. It’s bigger than Joshua-Parker or Joshua-Wilder, and even with Fury currently completely out of active competition, there’s a ton of interest there.

So they’ll keep talking smack until it happens, or forever even if it doesn’t, probably.