Cannes' humanitarian a trois: Sean Penn, Petra Nemcova and Bono?

The ongoing French romantic comedy ("Three Babes and a Jury President?") that has become Sean Penn's life during the Cannes Film Festival continues:

Last week, model Petra Nemcova, who had been romantically linked with a then-separated Penn earlier this year, briefly bared a breast on the red carpet at the Cannes premiere of "Un Conte de Noel."

Did Penn notice, attending with his pal Bono? The guys sure looked like they were sharing a private joke about something.

Saturday night, Penn and his stone-faced wife Robin Wright Penn, did a drive by Petra's Creative  Coalition fundraiser. And who was sitting cozy with Petra? Who else? Bono.   

Will Robin and Sean next attend his ex-wife Madonna's Cannes premiere of her documentary, "I Am Because We Are" on May 21?

Oh, this is gonna be a looooong festival.

To see pix of Sean and the long-suffering Robin, Petra with her new famous friend Bono, keep reading....

All Photos: WireImage