A Manhattan publishing executive told a pregnant subordinate that she should “try a sex toy” to stave off fatigue, according to a lawsuit.

McGraw-Hill Chief Information Officer December Martin was subjected to lewd comments by David Morales after she became pregnant in April 2008, says the suit, filed last week in Manhattan Supreme Court.

“Oh, you’re tired. You’re not having sex. Sex gives you energy,” Morales allegedly told her.

After Martin complained to human resources, her other boss, Patrick Dyberg, launched a harassment campaign that drove her to resign, the suit says.

McGraw-Hill denies all charges.

“We believe this claim is without merit,” said company spokesman Frank Briamonte. “And as a company recognized for treating its employees fairly, we will defend against it vigorously.”