Nina Agdal has a new boyfriend.

Nina Agdal

Nina Agdal

The 25-year-old model only split from her beau Leonardo DiCaprio in May but she's wasted no time bagging herself another boy as it's believed she's now dating Christie Brinkley and Peter Cook's son Jack Brinkley-Cook, 22.

A source told the New York Post newspaper's Page Six column: "It's serious. They are really cute together."

And the new couple aren't afraid to flaunt their new romance as they set tongues wagging recently when they were spotted smooching in public while in Montauk, New York.

Despite their very public display of affection, another insider insists they're merely having fun as part of the Fourth of July - a federal holiday in the United States commemorating the adoption of the Declaration of Independence - celebrations.

However, their lip-locking session will no doubt infuriate Leonardo as the pair only split up just over a month ago following a year of dating and vowed to remain close friends.

A source said: "They recently split up. They remain friends and are amicable. They are still talking and they remain close. They both felt the relationship had run its course."

The 42-year-old actor and the blonde beauty were first romantically linked when Leonardo invited Nina to accompany him to the Cannes Film Festival in 2016.

And just a few months later the pair were photographed kissing on a beach in Malibu, California.

In July, Nina's grandmother Lona confirmed the couple's romance, and jokingly warned the actor to "behave" around her granddaughter or else he would have to answer to her.

Lona said at the time: "We have not said hello to him [Leonardo] but we hope that he behaves towards her. Otherwise he will get me to deal with.

"I can tell you that it is six years since they first met, and now the relationship apparently developed."