When 50 Cent isn't making fun of other rappers with his Instagram posts, he's in the Instagram comments, making fun of other rappers. His latest victim is Fat Joe.

It turns out Joe isn't as fat as he used to be. But he's still not svelte enough to avoid a jab from Fif. 

"So this nigga trying to bring sexy back. Gym flow!" 50 typed sarcastically.

Fat Joe and 50 Cent had a lot of problems with each other 10, 15 years ago. But they buried all of that in 2012 after they came together to pay tribute to the late Chris Lighty.

But 50 isn't above mocking his "friends", especially when it comes to the gym. Just ask Jim Jones.