"They were obsessed with each other," the witness said. "They were kissing and making out everywhere. In the bathroom, at the bar, in the middle of the floor. They were basically having sex. There’s no question they’re together.”
The pair were previously seen cuddling, swimming and kissing together in Lake Como, Italy, in photos published the same day a rep for Cyrus and her husband, 29-year-old Liam Hemsworth, announced the couple of 10 years were separating after only eight months of marriage.
A source told Entertainment Tonight at the time that Cyrus and Carter, who was also fresh off a breakup from Brody Jenner, weren't trying to hide their affection for one another.
"They were fully on a date, getting drinks, just the two of them," the source said. "They even got a couple of massages at the hotel."
Cyrus and Hemsworth's rep earlier this month said the two "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."
But Cyrus' relationship with Carter, according to People, isn't just romantic — it's also a friendship. A source told the news outlet the women "are both going through similar stuff right now and are bonding over it."
Fox News' Jessica Sager contributed to this report.