It’s fairly common for a pair of Mixed Martial Artists to wage verbal warfare against each other, especially in this age of social media, but typically trash-talking stems from a desire to promote an upcoming bout between the two and involves run-of-the-mill bravado, plus perhaps a little posturing.

However, it’s rare when the involved parties are former training partners, one now being a UFC competitor and the other a retired-fighter-turned-broadcaster, let alone to see personal issues from the past brought up.

Such a situation unfolded Monday on Twitter when UFC welterweight Mike Swick took Strikeforce commentator Frank Shamrock to task for his involvement in an anti-bullying campaign. Swick’s issue apparently stemmed from what he felt was hypocrisy on the part of Shamrock based on things he experienced while the two trained together at American Kickboxing Academy.

Started Swick, “ARE YOU KIDDING FRANK SHAMROCK!?!? I have seen it all now! I usually keep my mouth shut and stay far away from any controversy or disputes with other fighters but this is too much! Frank Shamrock started a foundation to fight bullies because he was cyber-bullied?”

Further elaborating on the topic, Swick wrote, “…that’s ironic considering he was the biggest bully at our gym until we had to split him from our team. I can’t even list the fighters on the team that were injured and hurt by him and that he passed out in chokes even after they tapped. This is like making the drug dealer a cop so he can help them get more drug dealers.”

In response to the allegations, Shamrock posted, “Mike Swick calling me a bully is lame. I used to whoop his butt for sure cuz he wanted to be a champ. Always respect and love for him. Guess (he) forgot how I used to write his fan mail back when he (was) in the military. Or how I bled for him and trained him personally.”

However, the walk down memory lane didn’t earn a reprieve from the 14-4 Texan, who replied, “Come on Shamrock, if you’re gonna be an advocate, be a man…admit you were a bully – apologize. Bet that video never surfaces! Don’t be fake!”

“You define bully. Hurting smaller teammates on purpose. Choking teammates unconscious that tap,” he continued.

Though the discussion ended after Shamrock offered Swick an opportunity to talk in person if he was in San Jose, to which Swick said the former UFC middleweight champion had seven years to speak with him about it, it seems clear neither man will be sending the other a Christmas card any time soon.

Shamrock’s issues with AKA-trained fighters is nothing new, as his rivalry with Phil Baroni is well-documented in addition to the heat between him and former Strikeforce 155-pound champ Josh “The Punk” Thomson (who Shamrock once made reference to as “the first openly gay fighter in MMA”).