TOWIE star Mario took Buzz to a McBusted rehearsal earlier this week and was captured holding the tot as Tom performed on stage with his bandmates.
Given that he is only seven months old, little Buzz was wearing a pair of ear defenders for protection and looked as cute as a button!
Sharing the snap on Instagram, Mario commented: "We went to see his very talented daddy and his band at work! #mcbusted."
Mario's sister Giovanna - who is married to Tom - gave birth to Buzz in March and it's fair to say Mario has been a very hands-on uncle from the offset.
Whether it's babysitting duties, or simply a playdate, Mario has been keen to get involved in his nephew's life.
Meanwhile, after a tough few months Mario is back to his best and returned to The Only Way Is Essex last week (8 October) after taking a break from the show.
In August, Mario confirmed he had decided to skip series 12 and focus on his personal life after "going off the rails" following too much partying.
Mario made his return in the Ibiza special and it was very clear the tailor and reality star is firmly back on track.
Following his comeback, Mario received a lot of support online from fans and tweeted: "Thank you for all your lovely tweets... It's great to be back on the @OnlyWayIsEssex x."