Conor McGregor is back at it with Artem Lobov.

Once good friends and training partners, McGregor and Lobov had a falling out a few years ago when Lobov sued the former two-division UFC champion for millions over the Proper 12 whiskey deal that saw McGregor make $600 million. Things then continued to spiral as Lobov also sued him for defamation, prompting McGregor to challenge him to a fight. McGregor ultimately won the defamation suit, with Lobov being ordered to pay damages, but the Proper 12 legal battle continues, and on Friday, McGregor renewed his social media assault of his former friend.