07/30/2012 09:22 am ET Updated Jul 31, 2012

Kristen Stewart, Rupert Sanders Affair Went On For Months Says Director's Brother-In-Law

Rupert Sanders has stayed mum since publicly apologizing to his wife and kids for his affair with Kristen Stewart, but the same can't be said for the British director's brother-in-law.

"It was from the last half of filming and all through post-production, clear into last week," Leopold Ross told the U.K.'s The People of the couple's affair, which Stewart had originally called "a momentary indiscretion."

But Gossip Cop points out that Leopold never says he has any form of evidence or "first-hand knowledge" that his allegations of a long-lived affair are actually true. Plus, there's the obvious fact that his sister, Liberty Ross, is the one who is now left to pick up the pieces of her broken marriage -- a marriage for which she left Britain and moved to Hollywood.

And as if Liberty wasn't made to look like enough of a fool before, it's certainly only getting worse as details regarding what was initially described as a one-time hookup begin to surface. Hollyscoop reports that 41-year-old Sanders was "obsessed with" and pursued 22-year-old Stewart for months.

“He was absolutely infatuated with her,” a source told RumorFix. “He was after her for months but she was just in love with her boyfriend. She never chased him, never pursued him. He is much older than her and took advantage of his position. She was never a victim but he absolutely was the one to go after her. It was pretty obvious what was going on.”

Although Stewart has not spoken since releasing a statement to People following last week's distribution of incriminating photos illuminating Sanders and her romance, Robert Pattinson's actions seem to be doing all the talking. A "heartbroken and humiliated" Pattinson has reportedly packed his bags and moved out of the ex-couple's shared Los Angeles home.

"She was young and mistaken,” RumorFix's source continues. “She is a strong girl and admitted she was wrong. That statement was Kristen, totally her own voice.”



Kristen Stewart & Robert Pattinson