​Machine Gun Kelly wasted little time rubbing in Conor McGregor’s latest setback. Not long after McGregor suffered a devastating knee injury during his UFC 329 defeat to Max Holloway, the musician hopped onto Instagram to mock the former two-division champion. Tagging McGregor in posts that included footage from the fight, MGK mocked how quickly the Irish fighter’s knee gave way and teased that age had finally caught up with him. “Knees weak of old age the real Conor can’t stand up,” Kelly wrote, adding a clown emoji. The barb quickly reignited one of the more unusual celebrity feuds in recent memory.
The feud between the two dates back to the 2021 MTV Video Music Awards, when McGregor and Kelly were involved in a heated red-carpet altercation. Video footage from the incident appeared to show McGregor lunging toward the musician before security stepped in. Additional clips circulating online later showed drinks being hurled as the confrontation escalated. At the time, Megan Fox could be seen trying to separate the two men while security personnel worked to keep the situation from turning physical. Despite the viral moment, McGregor’s team played down the incident afterward, issuing a brief statement that read, “Conor only fights fighters.” Neither man has publicly buried the hatchet since.
Long before his knee gave out against Max Holloway, McGregor’s return to the UFC had become one of the most polarizing comeback stories in sports. Much of the criticism centered on a November 2024 civil court verdict in Ireland, where a Dublin jury found McGregor liable for sexually assaulting Nikita Hand during an encounter at a hotel penthouse in 2018. McGregor denied the allegations throughout the proceedings, but the court ultimately awarded Hand damages and later ordered him to cover substantial legal costs. The case drew international attention because Irish prosecutors had previously declined to pursue criminal charges, citing insufficient evidence to meet the higher criminal standard of proof. The civil case moved forward and ended with a jury’s finding against the former UFC champion. McGregor appealed, arguing that errors were made during the trial, but Ireland’s Court of Appeal unanimously dismissed those arguments in July 2025, leaving the judgment intact.
The legal issues did not end there. McGregor is also facing a separate civil lawsuit in Florida stemming from allegations that he sexually assaulted a woman in a bathroom at the Kaseya Center in Miami during the 2023 NBA Finals. McGregor has denied those allegations, and the case remains ongoing. The controversy surrounding McGregor’s comeback extended beyond the sports world when he appeared on The Tonight Show Starring Jimmy Fallon in June to promote UFC 329, an appearance that was widely viewed as part of a broader strategy to boost visibility for a high-profile return.