Conor McGregor appeared to spit on a Khabib Nurmagomedov supporter in Las Vegas recently ... with video of the heated altercation quickly making rounds on social media.
The clip shows Conor and his crew walking by Caffè Al Teatro inside the Wynn ... when someone nearby yelled out his support for Notorious' arch nemesis.
Conor did a heel turn and walked right up to the man responsible for the "Let's go Khabib" remark ... and seemingly let some saliva fly in his direction.