Spencer Pratt Sold Pics of Teen Mary-Kate Olsen Partying With Henry Winkler’s Son

Spencer Pratt started working on his reputation as a villain long before he became one on reality TV … he’s admitted he once sold snaps of a teenage Mary-Kate Olsen partying with her then-boyfriend, Max Winkler, for a whopping $50,000!

Spencer spilled the deets in his brand new memoir “The Guy You Loved to Hate: Confessions from a Reality TV Villain” … and he’s saying he doesn’t regret it a single bit.

Here’s the deal … he writes his pal Max — the son of actor Henry Winkler — had just gone through a split with Mary-Kate … but still had a “shrine” of photos with her in his room. He describes the images as “young love documented in European hotels, Hollywood parties, stolen moments.”

Well, Spencer thought he’d do his friend a solid by removing the party pics from his room … which Max apparently did not protest. But, instead of taking the photos to the trash … Spencer sold them to a photo agency, which then used them to spin a story about Mary-Kate having a bad-girl party phase.

Spencer writes in his memoir, he got $50K for the snaps, and used that to finance a film he wanted to make … though it never saw the light of day.

And even to this day, Spencer says he feels no remorse. He explains … “When you really think about it, it was a win-win. Mary-Kate got her rebel rebrand, Max got closure.”