State Attorney General Eric Schneiderman called his Sri Lankan girlfriend his “brown slave” and wanted her to refer to him as “Master,” the woman says.

Harvard-educated activist writer Tanya Selvaratnam told the New Yorker magazine that her yearlong affair with Schneiderman “was a fairytale that became a nightmare” — and quickly escalated into violence in the bedroom, even as he begged for threesomes.

“Sometimes, he’d tell me to call him Master, and he’d slap me until I did,” Selvaratnam said.

“He started calling me his ‘brown slave’ and demanding that I repeat that I was ‘his property.’”

Selvaratnam said, “The slaps started after we’d gotten to know each other.

“It was at first as if he were testing me. Then it got stronger and harder. It wasn’t consensual. This wasn’t sexual playacting. This was abusive, demeaning, threatening behavior.”

She said that as the violence grew, so did his sexual demands.

The abuse increased until Schneiderman was not only slapping her but spitting on her and choking her, she said.

“He was cutting off my ability to breathe,” she said.

Soon, “we could rarely have sex without him beating me.”

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