Conor McGregor just took his whiskey promotion to the next level. The Irish mixed martial arts (MMA) star has been brandishing his new Proper 12 Irish Whiskey brand over the past year.

McGregor takes a lot of pride in his new endeavor, and did not respond well this past April when a man at an Irish pub refused to share a drink with him. The incident took place from the Marble Arch Pub in Dublin on April 6. McGregor walked into the venue and riled up the bar-goers, pouring drinks for several men.

READ MORE:  Paddy Pimblett and the UFC facing backlash following 'Shameless' Tony Ferguson matchmaking

However, one elderly man took issue with McGregor causing a ruckus at the bar and refused not one, but two drinks from “The Notorious.” Thanks to some CCTV footage, we can see McGregor respond by punching the man in the face. McGregor is immediately dragged away by what are likely members of his own security team.

The incident was reported to local police who subsequently opened up an investigation. It remains unclear if that investigation is still ongoing or not. To the old man’s credit, he took the punch with little to no reaction, as he simply continued to sit on.

READ MORE:  Francis Ngannou reveals how a superfight with UFC champ Jon Jones could still happen

The Irish Mirror was able to obtain witness accounts from several people at the bar during the time of the incident. One said, “McGregor was being a show off in the pub and one man didn’t like it and went up to have a word with him.” Another added, “There was a bit of a commotion, he [McGregor] was acting the mick and there was an incident. There weren’t many people in the bar at the time, there was drink involved.”

READ MORE:  Conor McGregor urges veteran rival Nate Diaz to make UFC return for trilogy clash: 'I owe him a fight'

Check out the video below courtesy of TMZ Sports.

This is just one of several disturbing acts of violence from McGregor over the past year. McGregor has faced legal discipline for smashing a fan’s phone outside of a nightclub, been arrested for tossing a dolly through a UFC fighter bus window in New York and injuring several people, and also had sexual assault allegations brought against him several months ago.

What do you think about McGregor punching the elderly man over the whiskey dispute?