Sean Penn made a cryptic comment during his presentation of the best actress Oscar on Sunday night. We assumed he was speaking of his estranged wife, Robin Wright Penn, when he said. “I never became an official member of the academy, but the academy and I do have in common that we neglected to acknowledge the same actress in our own ways two years running.” Penn neglected to thank his wife in his Oscar acceptance speech last year, and the two split soon afterwards. (They’ve had an on-off relationship and did reunite at least once, but have since moved forward with their divorce.) The Academy didn’t nominate Robin for The Private Lives of Pippa Lee this year, which is thought to be what Penn was referring to. (As far as I can tell, she was only in one film that came out in 2008, What Just Happened.)

Anyway after the ceremony Penn was said to have been involved in some kind of vague altercation backstage with Robin’s new boyfriend, Greg Shapiro, a producer of The Hurt Locker. Words were (allegedly) exchanged and Penn was perhaps later barred from the Govenor’s Ball post-Oscar party. A rep from the Academy denies that Penn was unwelcome at the party and Penn’s rep says he just didn’t go to that affair.

The Milk star apparently had some sort of backstage confrontation with Greg Shapiro, one of the newly minted Oscar-winning producers of The Hurt Locker. But if you think it could have had something to do with Penn’s politics and the war movie, not so fast…

Shapiro happens to be dating Penn’s former ladylove, Robin Wright.

Minutes after Penn and Shapiro came face-to-face, “Academy officials…said he was banned from the Ball,” one of my sources said.

Penn’s rep insists there was no confrontation and that the actor chose not to stop by the Ball. A rep for the Academy would only say, “Sean Penn chose not to attend the Governors Ball.” (Update: Late this morning, another rep for the Academy emailed me, insisting that Penn was never not welcome at the Ball.)

Penn eventually made his way to the Sunset Tower Hotel afterparty. “Fine,” he told E! News’ Ashlan Gorse when she asked him how his night was.

Earlier in the day, Wright and Shapiro appeared to be very much a couple—and a very happy couple at that. I actually saw them enjoying a meal at Cheebo in L.A., where they canoodled over breakfast while reading the Los Angeles Times together.

[From E! Online]

It’s hard to tell if this story is true, but since this is the same guy who just wished rectal cancer on his detractors, I don’t doubt it. He was thinking about Robin enough to say something unsanctioned at the Oscars, and I could see him getting up in her new boyfriend’s face. Maybe it was just a minor exchange that’s being blown out of proportion, though, especially in Penn’s estimation. He could have been gruff and rude to the guy, but it’s not like that’s out of character for him.