Chicago- It’s a case of conception – by alleged deception.

A Chicago doctor claims his ex-fianc̩e stole his sperm by performing oral sex Рand then used his seed to impregnate herself.

Richard Phillips admits that six years ago he and Sharon Irons, also a physician, had a brief romance.

He insists that during that time they had oral sex three times – but no intercourse.

But Irons’ lawyer said Phillips is simply trying to get out of paying child support for their 5-year-old daughter.

“It’s the first time I’ve had a guy use this excuse,” the lawyer, Enrico Mirabelli, said. “His complaint is the best work of fiction I have read since ‘The Da Vinci Code.'”

In a lawsuit alleging that Irons engaged in “extreme and outrageous” conduct, Phillips claimed she used subterfuge to get pregnant. He said he broke off their relationship after discovering that Irons was still married.

The Illinois Appeals Court last Wednesday agreed that Phillips, 54, can press a claim for emotional distress, but ruled that Irons didn’t steal the sperm.

“She asserts that when plaintiff ‘delivered’ his sperm, it was a gift,” the decision said. “There was no agreement that the original deposit would be returned upon request.”

The court did not rule on Phillips’ claim on how Irons got pregnant and sent the case back to Cook County Circuit Court.

“It’s a pack of lies,” Irons, 40, told the Chicago Sun-Times.

Irons said Phillips got her pregnant the old fashioned way and was “very happy” at first. But when Phillips got cold feet and split, Irons said she had to haul him into court to get $800 a month in child support.

Several fertility experts told the Sun-Times the sordid scenario Phillips described could “theoretically” result in a pregnancy.

Four years ago a sperm-stealing story involving Boris Becker made headlines.

The Teutonic tennis star had a three-minute encounter in a London lavatory with a Russian model. Eight months later, Becker was informed he was the father of a daughter.

At first Becker denied the girl was his and his public relations people spun lurid stories suggesting the model had “stolen” his sperm. When DNA tests confirmed the child was Becker’s, he agreed to pay up and the stories went away.