KATE WARNS LEO 'CLEAN UP YOUR ACT!'

A TITANIC MISSTEP HAS PUT THEIR FRIENDSHIP ON ICE

From career highlights to personal heartache, best friends Kate F Winslet and Leonardo DiCaprio have stood by each other through it all.

But Leo's recent return to his playboy ways are starting to put a bad taste in Kate's mouth, and the actress has warned it's time he got his act together!

"Leo's incredibly talented and Kate will adore the man forever, but his lifestyle and immaturity, when it comes to his personal life, is just a whole different world to hers," says an insider.

The pair, who worked together on Titanic and Revolutionary Road, have been in talks for the past two years about finding a new project to star in.

However, sources confirm Kate's initial excitement over reuniting with Leo, 48, for a third film has waned significantly.

"Kate's team have lost all enthusiasm for this project and it's not hard to see why," says an insider.