05/25/2009 at 09:00 PM EDT
Looking relaxed and clean-shaven in jeans, a white shirt and a blue jacket, actor and director Mel Gibson gamely answered questions about his relationship with musician Oksana Grigorieva
and confirmed her pregancy
during his 21st guest appearance on NBC's Tonight Show
, airing Monday night.
In fact, Jay Leno set the tone for the evening by saying there were a lot of rumors to clear up. He then asked Gibson about his split with Robyn, his wife of 28 years.
Gibson, 53, said he took the blame for the divorce
. "My wife and I, our marriage ended three years ago and we've been separated ever since then," Gibson said. "These things happen. It's unfortunate, it's sad, but you know she is an admirable woman – we still got kids together. We're friends."
When Leno pressed Gibson by asking, "So what happened?" Gibson replied, "Look. When it's all said and done, I did a pretty good hatchet job on my marriage myself. I'm to blame. If you're inclined to judge, put it here."
Leno then joked with Gibson about his dating a younger woman. "What, is she 17, 18?" Leno asked. Gibson replied that Grigorieva was almost 40 and "now I am going to have two women mad at me!" Leno then said, "The rumor I have heard is that you guys are going to have a child?" Gibson then confirmed, "This is true. We're gonna have a child."
Piling it on, Leno joked, "So that will make 29? " Quickly, Gibson responded, "Well, actually eight. I guess I'm Octo-Mel."
Gibson is among the first of many special guests
in Leno's last week as host of the Tonight Show
, with his final guest on Friday being his successor, Conan O'Brien, who takes the helm on Monday, June 1. Leno returns to NBC in the fall in primetime
Reporting by Esther Zuckerman