Lena Dunham has said she flirted with co-star Brad Pitt on the set of Quentin Tarantino’s “Once Upon a Time in . . . Hollywood” — but the “Girls” creator took things to the next level at the film’s London premiere.

When the cast lined up on the red carpet, Dunham was separated from Pitt by Tarantino and stars Leo DiCaprio and Margot Robbie.

But she made her way to Pitt and went in for a kiss on the lips.

She caught about half his mouth.

In the movie, she plays a Charles Manson follower.

She tweeted: “It’s not every day I get to wear a mumu, go barefoot, flirt with #BradPitt, and join a cult . . . as a job.”