Elizabeth Holmes' Fiancé Says He Feared She Might Be Scamming Him

Elizabeth Holmes' fiancé says he fell for her before he even knew she was the woman behind Theranos ... and Nathan Fielder wastes no time putting that love story through the fraud test.

Billy Evans makes the eyebrow-raising admission in the trailer released Wednesday for the upcoming documentary, "You Can See Everything" ... which follows Holmes in the final weeks before she reported to federal prison.

"I fell in love in that first conversation," Evans says.

Billy says it was "probably before" Holmes revealed she founded Theranos ... prompting Fielder to ask if he ever worried she was scamming him too.

"100%," Evans says ... prompting Fielder to point out Holmes may have had something to gain.

"Well, isn't your family rich?" he asks ... with Evans replying, "Yeah, I think that there's like a lot of different levels of wealth."

Of course, the question carries some serious baggage. Holmes was convicted on federal fraud charges stemming from Theranos, the blood-testing company that once made her one of Silicon Valley's biggest stars before its claims unraveled.

The documentary started filming 34 days before Holmes went to prison in 2023 to serve her 11-year sentence ... with Holmes saying she wanted to capture her story "before I'm gone."

And the trailer ends on an unusually emotional note ... with Holmes admitting, "It took me a really long time to be OK with letting someone see me cry."