Gavin Newsom's Ex-Lover Details How Affair Unfolded, Claims Kamala Gave Her Advice

Gov. Gavin Newsom's former lover is pulling back the curtain on their affair ... revealing the lengths she went to get him alone -- and the advice Kamala Harris gave her when the scandal exploded.

Ruby Rippey writes in a new Vanity Fair essay that professional boundaries with Newsom began crumbling while she worked as his secretary during his time as San Francisco mayor.

Rippey says she would scan Newsom's calendar for openings, show up wherever he was expected to be and make sure he spotted her before slipping away. She says her phone would soon light up with a text asking, "Where are you?"

The location apparently didn't matter ... because Rippey says she always went to him ... whether at his Russian Hill penthouse, a private room inside a North Beach bar or the W Hotel in Los Angeles.

A rep for Newsom tells TMZ ... "The Governor acknowledged his role and publicly apologized nearly two decades ago when he was still mayor. In the time since, he met his wife, started a family and has focused on serving Californians."

The rep says Newsom "addressed this chapter of his life, including in his memoir, and, out of respect for everyone involved, has nothing further to add."

Rippey -- who at the time was married to Newsom's close friend and campaign manager, Alex Tourk -- says the relationship wasn't about love or romance. She describes it as another form of intoxication during her struggle with alcohol and cocaine ... fueled by proximity to power and the feeling of being chosen.

She entered rehab in May 2006 and ended the affair, but did not confess to Alex until January 2007. He later confronted Newsom and resigned, and Newsom publicly admitted the affair and apologized.

Rippey says Harris -- then San Francisco's district attorney -- called after the news broke. Rippey was broke, unemployed and considering a memoir offer when Harris urged her to hold off.

"I wouldn't say anything right now, Ruby," Harris allegedly told her. "Just pause. More time will give you better perspective."

Rippey took the advice and stayed largely silent. She now says she accepts responsibility for her choices while also recognizing Newsom held the greater power in their working relationship.