Photos obtained by Entertainment Tonight show Cyrus, 26, and Carter, 30, cuddling, kissing and swimming together in Lake Como, Italy, where they're currently vacationing with Cyrus' big sister, Brandi.
In one photo, Carter's hand is on Cyrus' derriere inside of her bikini bottom.
A spy told the outlet, "They were not trying to hide it at all. There were other people sitting by the pool."
The witness also added, "They were fully on a date, getting drinks, just the two of them. They even got a couple of massages at the hotel."
The photos were released mere hours before Cyrus' rep confirmed the "Mother's Daughter" singer and Hemsworth, 29, had called time on their eight-month marriage.
The statement from the former "Hannah Montana" star's rep says, "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 their animals they share while lovingly taking this time apart. Please respect their process and privacy."
Cyrus herself appeared to hint at the split in a tweet Sunday, captioning two photos, “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, it was over millions of years that this magnificent beauty was formed.”
Carter and Jenner, 35, announced their own breakup last week.
The pair, who appeared to have tied the knot in Bali, Indonesia, in June 2018, were never legally married.
Cyrus and "The Hunger Games" star Hemsworth married in December 2018 after losing their Malibu home to raging wildfires in California. The couple had previously dated off and on for nearly a decade after meeting on the set of "The Last Song" in 2009.
"I’m in a hetero relationship," Cyrus said, "but I still am very sexually attracted to women. I made a partner decision. This is the person I feel has my back the most. I definitely don’t fit into a stereotypical wife role. I don’t even like that word.”
Fox News' Brie Stimson contributed to this report.