The 51-year-old star and his Bros bandmate live in separate cities in the US, but they're in daily contact with each other and retain a strong bond.
Luke - who lives in Los Angeles while his brother resides in Las Vegas - shared: "My brother and I shoot the s*** about life and the band and business opportunities a minimum of once a day, at most four times a day.
"And we tell each other we love each other on every call, once at the beginning and once at the end and once in the middle."
In 2018, Bros were the focus of a hit documentary film that charted their rise and fall, as well as the preparations for their reunion in 2017.
And Luke has admitted that 'Bros: After the Screaming Stops' helped to change his "relationship" with the British public.
He told the Daily Mirror newspaper: "There is lots of love and hugs now.
"There was only one debate going on at the time - Brexit. And then the doc came along...
"I think there was some compassion applied to Matt and I and I think that was a beautiful credit to the country. They saw we were just a couple of lads ... trying to work through life like everybody else and there was this big dump of candour.
"From what I've been told, people were just hungry for some truth.
"There was tension because we were learning to play together again as a band and I had to use all my meditation and prayer practices to relax.
"It allowed us to get things off our chests but I hope it also corrected some of the misconceptions about us that were radically inaccurate."
