"It’s definitely unacceptable and I immediately wish I would have took it back," Trav told brother Jason on the newly released episode of their "New Heights" podcast.

Thankfully, there doesn't appear to be any hard feelings between coach and player ... T.K. says he had a conversation with Reid on the field soon after the incident, and they're cool. Winning the Super Bowl also doesn't hurt.

“I just love playing for the guy and unfortunately, sometimes my passion comes out where it looks like it’s negativity but I’m grateful that [Andy] knows that it’s all because I want to win [the Super Bowl] with him more than anything,” Travis added.

Jason, who used to play for Reid in Philadelphia, was also critical of his brother's actions.

"You crossed the line, I think we can both agree on it," JK said, with Travis ... "I did."

Jason added ... "Let's be honest, the yelling in his face too is over the top. I think there's better ways to handle this, retrospectively."

Of course, Travis and Andy go back to 2013 when both men arrived in Kansas City.

Not everyone seems willing to just brush off the exchange and move on ... including some fellow NFL stars like A.J. Brown, who claimed he "would've been kicked out of the league" if he pulled a Kelce.

Travis seems unbothered by the outside criticism.

"I don't give a s*** what anybody else says."

Inside the org, everything appears to be great ... in fact, Reid and Kelce are together at the parade as we type.