Maybe Leonardo DiCaprio just does not know how to stay in a committed relationship. While in Miami at the Art Basel, the actor reportedly had a steamy make-out session with a woman who was not his girlfriend. DiCaprio has been dating Victoria’s Secret model Toni Garrn since at least the summer.

However, while in Miami Thursday morning, at 3:30 a.m., a source tells the Daily News’ Confidenti@l, the 39-year-old kissed a brunette woman at the W Hotel’s Wall nightclub.  “One beautiful super-young brunette launched into him, hugging him with both arms, and gave him a passionate French kiss with tongue! They kissed a couple of times. The encounter was getting pretty hot. He was super into her.”

His friends tried to deny the report, saying the woman was the girlfriend of one of the actor’s close friends, and “was kissing him on the cheek because he bought a piece of art from him. She was kissing his face like crazy because it was a huge deal.”

Garrn got her modeling break in 2008, when she landed a Calvin Klein campaign. The actor has dated a slew of beauties over the years, such as Victoria’s Secret models Erin Heatherton and Gisele Bundchen.

The beauty just celebrated DiCaprio’s birthday with him in November.

Meanwhile, DiCaprio is starring in the upcoming “The Wolf of Wall Street” as Jordan Belfort, an uber-wealthy New York stockbroker in the ‘80s. The film comes out on Christmas Day.