Vickers has lifted the lid on a "bizarre" encounter she once had with DiCaprio after being invited to his home.
The 34-year-old singer opened up about the experience while chatting with her "Just Between Us" podcast co-host, sex columnist Alice Giddings, during a discussion about relationships with large age gaps.
Vickers recalled that she was introduced to DiCaprio years ago through one of his friends, who invited her over under the impression that it would be a lively gathering. Instead, she "ended up just sitting with him watching telly."
"It was a really, really bizarre moment," Diana admitted, adding that the Oscar winner likely wouldn't even remember their brief meeting.
Reflecting on the moment, she described DiCaprio as "a man in Hollywood with so much fame and power, who doesn't want to grow up," and speculated that she was far from the only young woman casually brought around by his inner circle.
"I think he has this system," she noted.
According to Vickers, DiCaprio tends to keep a circle of attractive male friends who, in turn, "source these hot women for him."
"That stuff happens a lot in Hollywood. These men have got so much fame and power, and they don't want to grow up," she remarked. "They just want to be surrounded by beautiful young women all the time. I am not generalising Leo here, I think that's just what happens. It's quite weird, actually."
The former "X Factor" star shared her story during a podcast episode where she and Giddings took a call from a listener named Hannah, who was struggling in her relationship with an older man.
Vickers admitted she's dated both younger and older men herself, but said that relationships with younger partners were more challenging for her due to their "immature energy."
"A lot more women are dating younger men now," she shared. "One of the last guys I dated was five years younger than me – I did feel it. It was why we didn't work out. When you're older, you want to put in the graft – you want to see things through. You don't dwell on smaller things as much."
She added, "This guy just gave off immature energy – he was constantly holding on to things. I think I may have acted immaturely because he was less mature. It made me feel less of my older, feminine energy. I sort of reverted back. It was a lot of fun, though."
Meanwhile, DiCaprio was recently seen spending a day at sea with girlfriend Vittoria Ceretti, 27, in Ibiza.
DiCaprio showcased a noticeably slimmer physique in blue swim trunks, while Ceretti drew attention in a revealing thong bikini that highlighted her toned frame.
The model paired her look with a casual baseball cap while moving around the yacht.
The yacht sighting comes shortly after DiCaprio made unusually candid remarks about his dating life.
Speaking in an interview with Esquire UK for its Autumn issue, the Hollywood star admitted that at his age, "there is no time to waste" when it comes to relationships.
Reflecting on the challenges of dating as an older man, DiCaprio said he feels the need to be more direct about what he wants from a partner, even if that honesty can sometimes cause relationships to break down.
He added that reaching 50 has prompted him to think differently about the future.
DiCaprio and Ceretti were first linked in August 2023, marking one of the actor's most high-profile relationships in recent years.
Before dating the Italian model, he famously ended a five-year relationship with actress Camila Morrone in 2022, just a month after she turned 25.
Over the years, DiCaprio has been connected to several well-known models, including Gigi Hadid, Nina Agdal, and Toni Garrn. This pattern has fueled a longstanding public narrative that he rarely dates women past their mid-twenties.
However, not all of his exes share that view. Kristen Zang, who dated the star in the 1990s, defended him in 2022, clarifying that she was the one to end their relationship after realizing she had "outgrown" it.
