An LGBT group is firing back at Floyd Mayweather for using a homophobic slur at Friday's press conference in London ... saying his reason behind using the word is complete B.S.
Floyd ripped into Conor McGregor at the final stop on the superfight's world tour ... calling him a string of names, including a gay slur.
Hudson Taylor, executive director of Athlete Ally -- an org. that promotes LGBT acceptance in sports -- took notice and denounced Floyd's actions, telling TMZ Sports: "Athlete Ally strongly condemns the homophobic slur used by Floyd Mayweather."
"The response given by Mayweather's representative is equally troubling. If Mayweather truly has the utmost respect for the LGBT community, he wouldn't resort to using slurs that perpetuate anti-LGBT stigma and hate."
Taylor goes on to address McGregor's alleged involvement, saying, "Resorting to homophobic and racial epithets is shameful no matter how or why one uses them."