A pricey Manhattan law firm pumped up the animosity against a breast-feeding employee, according to a lawsuit.

Legal assistant Hannah Kim claims she was subjected to “severe harassment” at white-shoe firm White & Case when she needed to express milk, and was even ordered not to leave her office to use the company lactation room, according to court papers.

Kim then had a lock installed on her office door so that she could pump in privacy, but that didn’t stop coworker Carol Grajeda from “aggressively” trying to open the door repeatedly, she charges in her Manhattan Supreme Court papers.

Another woman frequently attempted to interrupt Kim’s pumping by claiming to have something important to discuss, but would then just deliver office gossip, Kim claimed in court papers. The colleague, Rita Masino, also derided Kim’s choice to breastfeed for more than two years, telling her that her son was a “grown-ass boy,” according to the legal filing.

Even before she gave birth, bosses were hounding Kim, she says. One “called her into his office and described his own wife’s labor, postpartum recovery and changes to her body, including intimate details about his wife’s vagina.”

White & Case declined comment. Grajeda and Masino could not be reached.