"You don't understand what it's like," he replied. "I don't want to talk about it, mate."
On Saturday night, Cyrus, 26, and Hemsworth announced their separation after eight months of marriage and more than a decade of an on-again-off-again romance. Hours earlier, photos were published of the "We Can't Stop" singer kissing Brody Jenner's ex, Kaitlynn Carter, while vacationing in Italy.
Cyrus' rep said in a statement: "Liam and Miley have agreed to separate at this time. Ever-evolving, changing as partners and individuals, they have decided this is what’s best while they both focus on themselves and careers. They still remain dedicated parents to all of the animals they share while lovingly taking this time apart. Please respect their process and privacy."
Some reports suggested Cyrus wanted an open relationship with Hemsworth that allowed her to "have fun" with other men and women while remaining married to the "Hunger Games" star.
Cyrus herself hasn't publicly addressed the split specifically but did write a note on Instagram echoing her publicist's statement about "evolving," writing, “Don’t fight evolution, because you will never win. Like the mountain I am standing on top of, which was once under water [sic], connected with Africa, change is inevitable. The Dolomites were not created over night [sic], it was over millions of years that this magnificent beauty was formed.”
Over the weekend, Jenner, 35, commented on photos of Cyrus and Carter, 30, writing, "hot girl summer."
He later posted, "Don't let yesterday take up too much of today."
His pal and fellow "The Hills: New Beginnings" star Brandon Thomas Lee — son of Tommy Lee and Pamela Anderson — commented, "Let's round this scandal our band post a pic of us making out."
Jenner replied, "Watch out! Pics of Liam and I holding hands on the beach coming soon."
Upon seeing the comments, the former "Hannah Montana" star replied to Jenner, "Go take a nap in your truck and cool off. #HotGirlSummer."