McFly star Tom is married to Mario's older sister Giovanna and they have spent the last week in the Mediterranean visiting Falcones' 95-year-old nonna (grandmother).
During their trip, Tom made a short video for his weekly 'Dear Carrie' blog and, it is clear to see, he and former TOWIE star Mario have something special!
In the short film, the pair are seen out running together and also hanging out with Tom and Giovanna's two children, Buzz and Buddy. But it gets better - they talk about sharing a chocolate croissant, Mario gives Tom a cheeky pat on the bottom and they even recreate the Titanic 'flying' scene.
When chatting about their shared snack, Tom tells fans: "This is my brother-in-law Mario. Mario Falcone. We've stopped off to get a sandwich. We haven't eaten yet..oh yes we have - we shared a chocolate croissant. I had half of Mario's chocolate croissant. It was very nice."
The video is around seven minutes long and, to begin with, we were worried Tom's wife Giovanna would barely get a look in. But thankfully, she did towards the end!
Tom and Giovanna are childhood sweethearts, meaning Mario has practically grown up with the musician.
He is a proud uncle to Buzz and Buddy and often gets a mention in the couple's YouTube blogs. However, Giovanna did previously admit to never watching Mario when he starred in TOWIE, as she found it too weird.
We wonder if Tom did...?
Watch Tom's holiday video here: