Ellen Pao talks about an affair with a co-worker at Kleiner Perkins that she says made her job difficult

AP/Eric Risberg

Ellen Pao took the stand in her sex discrimination suit against venture capital firm Kleiner Perkins on Monday, where she gave her side of an affair she had with one of the firm's former partners, Ajit Nazre.

The affair with Nazre is important because, in Pao's telling, it reveals that Kleiner Perkins was a challenging environment for a female to thrive.

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Pao alleges Kleiner - and Nazre himself - retaliated against her after she ended the affair and told other partners about it.

"[Nazre] began pursuing me around February 2006," said Pao. "I told him I wasn't interested."

Pao said Nazre told her he was having marital problems.

"He continued to pursue me," Pao said. "He was relentless. He eventually told me his wife had left him."

Pao says only after Nazre told her he had left his wife - which turned out not to be true - did Pao acquiesce to a relationship. Pao says the relationship was "off and on" and lasted about 6 months.

The affair came to an abrupt end when Pao found out from someone else that Nazre hadn't left his wife.

"It had been rocky for a while and when I found out he had lied to me and that his wife had not left him I ended it immediately and permanently," she said.

Pao said she was "furious" and "felt manipulated and deceived" when she heard Nazre was still married.

Pao claims Nazre was hostile and made her job harder after it ended. He was eventually fired in 2012 after Kleiner found out he had been sexually harassing another partner.