Gay model Kerrick Ross is claiming he had a clandestine two month affair with Dannielynn’s daddy, Larry Birkhead.

“America doesn’t know the whole story about Larry Birkhead,” Kerrick, who’s 38 and lives in Louisville, Ky., is telling the tabs.

“He apparently had sex with Anna Nicole and fathered her baby, but there is no question: He also had sex with me!”

The two met at a cocktail party in Louisville around mid-2000 when Birkhead was a struggling real estate agent and writer, angling for a show business career in Hollywood.

“We were together for about two months and had sex eight to 10 times, always at my apartment. He often spent the whole night with me.”

According to Kerrick, Larry insisted on keeping their romance a secret. “I had been ‘out’ for a long time, but Larry was not out of the closet — and he was terrified about his family, who were devout Southern Baptists, finding out he was having a gay relationship,” revealed Kerrick.

“He was especially afraid of his father finding out. He said, ‘If my Dad knew about this, he would kill me!’