Earlier this year in March, Mario's sister Giovanna Fletcher and her husband, McFly's Tom Fletcher, welcomed their baby boy Buzz and ever since his birth, Mario has been known to share a sweet snap or two of himself and the little guy.
Today was no exception as the reality star couldn't resist taking a quick photo of the pair taking a little time out.
In his picture, Mario cutely mimics Buzz, who seems more than happy surrounded by toys on his baby mat, lying down on the floor side-by-side his nephew.
Captioning his photo, Mario said: "We chilling!" - they sure look like they've found a good spot.
Doting uncle Mario has enjoyed spending some quality time with Buzz lately and taking plenty of snaps of Buzz and himself. The pair have been enjoying naps, striking poses and lots of cuddles - who knew babysitting could be so much fun!
In one super-cute photo, Mario and Buzz can be seen pulling funny faces together. Posing like a pro, Buzz wasn't phased about being papped as he worked the camera while his uncle hilariously copied behind him.
New double-act in the making, perhaps?
Despite looking like they're having plenty of fun together, it seems becoming an uncle has had quite the impact on Mario.
Cuddling up to Buzz in another picture he shared over the weekend (6 September), Mario hinted that he is keen to put his ladies man rep and party lifestyle behind him.
Accompanying his shot with a touching message, Mario wrote: "There comes a turning point in life when you want to change your ways and better yourself and ways ... This little man was that point! X."
Does this mean we're going to see a new side to our returning TOWIE star?
Having spent the last series of the show off camera, last week Mario hinted he would be returning to TOWIE for its thirteenth series as he joined the rest of the cast to film the promo for ITV's new channel ITVBe - the new home of TOWIE - at Pinewood Studios.
Since filming, a TOWIE spokesperson has told Reveal: "The production team are in contact with Mario and he is taking steps to secure a return to the show."
The Only Way Is Essex kicks off again next month on 13 October.
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