Diane Keaton accuses Stephen Colbert of being a “sexual pervert” in just one of many super awkward moments on Monday night’s ‘Colbert Report.’

The Oscar-winning actress — promoting her memoir — was combative, giddy, and did anything but talk about her book, with some concerned viewers even suggesting she was drunk!

If Keaton was goofing around, she should have let Colbert in on the joke as a bemused but smirking Stephen asked “Before I encourage my viewers to buy the book, you have to say one f**king thing about it…You want to read the Library of Congress number or something?”

As to why Keaton called sweet, innocent Stephen Colbert a “pervert”… well, let’s just say it had something to with a backstage hug and Stephen’s butt.

For the record, TheHubNow can’t say if Keaton was intoxicated or kookylicious… but watch the weirdest celebrity interview we’ve seen in a long time and tell us what you think.