Two fired caretakers for Koko (search), the world-famous sign-language-speaking gorilla, have sued their former bosses, claiming they were pressured to expose their breasts as a way of bonding with the 300-pound simian.

Nancy Alperin and Kendra Keller, both of San Francisco, claim they were subjected to sexual discrimination (search) and then wrongfully terminated after reporting health and safety violations at Koko's home in Woodside, an upscale town in the south San Francisco Bay area.

The lawsuit against the Gorilla Foundation (search) and its president, Francine "Penny" Patterson (search), the longtime trainer of the well-known gorilla, was filed this week in San Mateo County Superior Court. It seeks damages totaling more than $1 million.

Foundation attorney Todd Roberts said the case mischaracterizes the foundation and turns a "purported employment issue" into publicity "hurtful" for a reputable organization.

"We unequivocally deny these allegations and are confident that this case lacks merit," Roberts said.

Alperin and Keller were hired last year and were among 16 employees of the foundation, which was founded in 1976 to promote the preservation and study of gorillas. It is best known for Koko, who has mastered a vocabulary of more than 1,000 signs; the foundation says she has advanced further in language than any other non-human.

The suit claims Patterson pressured the two women on several occasions to expose their breasts to Koko, a 33-year-old female — sometimes in situations where other employees could potentially view their bodies. The women never undressed, said their attorney, Stephen Sommers of San Francisco.

They were threatened that if they "did not indulge Koko's nipple fetish, their employment with the Gorilla Foundation would suffer," the lawsuit alleged.

The lawsuit claims that on one occasion Patterson said, "'Koko, you see my nipples all the time. You are probably bored with my nipples. You need to see new nipples.'"

In addition to the alleged harassment, the two former workers claimed the Woodside facility had unsanitary and unsafe conditions, including rodents in the food preparation area and gorilla urine stored in the refrigerator where workers kept their lunches.

They complained to the California Division of Occupational Safety and Health and were fired on Aug. 6, the day after inspectors visited the site and found code violations, according to the lawsuit.

The lawsuit also claims the nonprofit failed to pay for overtime and provide rest breaks.