Okay, so who's surprised that Leonardo Dicaprio likes to date models? Nobody, right? Leo had a nice long relationship with Victoria's Secret model Gisele, and has most recently been dodging engagment/baby rumors with current steady, Bar Refaeli.

But Bar wasn't the model on his arm late Friday night at Marquee. Onlookers say that James Blunt's ex Petra Nemcova and Leo were quite the cozy twosome at the club.

"He looked like he was all over her," says a witness."They were together from before 12:30 to around 2:30. He was holding her waist and touching her arm. Also, he was smoking up a storm - chain-smoking, almost."

The spy felt the need to express that, although the pals were, ahem, friendly, nothing indicated that Leo was messing around behind Bar's back.

Uh-huh. Then why tell the story at all, big mouth?