Fatone was taking part in a live chat with The Huffington Post when he was asked for his opinion on the fact that the I Want It That Way hitmakers are still touring 21 years after they first shot to fame.
He said, "I feel like they just need the money. No offence, guys. But I'm saying, if you think about it, it's like, 'Why are you coming back out again?'"
Carter heard about the slight while on his honeymoon with new wife Lauren Kitt, and he has expressed his disappointment at his pop peer's remarks.
In a post on Twitter.com, he writes, "Just disappointed, I really liked Joey... I'm proud of who we are and love what we stand for. Truthfully it's about not letting our fans down. Sorry bro but you have us all wrong. Now let me go back to enjoying my honeymoon."
Backstreet Boys: Show 'Em What You're Made Of is in cinemas nationwide for one night...