Time really flies fast. One decade, Bill Russell is giving Charles Barkley important lessons in life and finances, then in another decade, he’ll be flashing the former Philadelphia 76ers the bird.

That’s apparently what happened Monday night, when the Boston Celtics’ living legend was caught by cameras dishing off the one-finger salute to Barkley, who was on stage. You can’t make this stuff up, folks.

Go see for yourself below, via Def Pen Hoops:

It’s all in jest, though. Russell does not have any real beef with Barkley. If anything, it’s just a show of good, old Celtics-Sixers rivalry.

Bill Russell has won 11 NBA titles and five MVP awards, so he can do whatever he wants. Being old also comes with such perks, as gestures like that from senior citizens tend to come across as adorable than shocking. Everyone in the building had a good laugh, while people on Twitter are nearly losing it over Russell’s hilarious and spontaneous reaction.

Also, this is not the first time that Russell owned Barkley. Back in May, the basketball Hall of Famer said that Barkley had a higher chance of getting hit by lightning than stopping him on the court.

Russell is a treasure and a legend. Never change, Bill.