Footballer Josh, 25, played the clip while giving his speech at 28-year-old Mark's wedding last month.
It starts off with them as kids, and Mark, Josh and their big sister Jess, 30, are opening their Christmas presents.
Mum Carol also makes an appearance in the vintage clip, as the kids excitedly unwrap their gifts.
Then a series of snaps of Mark and Josh as children, teenagers and adults are shown on the screen.
At the end of the heartwarming video, a snap of Josh and Mark out for dinner flashes up with the words 'with love Josh'.
Posting it to Twitter, Mark wrote: "Check out this video that my bro @Joshwright4 played during he's speech at the wedding #brosforlife Josh and Mark [sic]."
Mark and Michelle Keegan, 28, tied the knot last month in a lavish ceremony at Hengrave Hall in Bury St Edmunds.
Following the big day, the couple jetted off on a two week honeymoon to the Maldives and Dubai.