THA BIRKHEAD

Yesterday, OK! magazine claimed that it had uncovered shocking allegations that Larry Birkhead is a shady and dishonest person.

The mag says it will reveal its explosive findings in their new issue.

Well, now Anna Nicole's ex is firing back and threatening to sue OK! magazine.

Birkhead claims that it's OK! that is behaving inappropriately.

"OK! magazine, they're basically-it's just sour grapes from them," Larry responds.

Birkhead said he planned to sue OK! for "alluding to the fact that I'd be involved in anything ethical or immoral with my daughter."

Dannilynne's dad said he believes the magazine's "explosive allegations" are culled from former MSNBC host Rita Cosby's upcoming book, Blonde Ambition: The Untold Story Behind Anna Nicole Smith's Death. He said he also plans to sue Cosby.

He's just sue happy!