Erik Menéndez Hugged Actor Portraying Him In Netflix Drama After Slamming Show

Erik Menéndez hasn't held back on his negative reaction to Ryan Murphy 's new Netflix biopic series about him and his brother Lyle -- but the actor who plays him says it was all love behind the scenes.

Cooper Koch said when he rolled up to San Diego’s Richard J. Donovan Correctional Facility with Kim Kardashian to meet the bros last week, he dove right in to hug Erik and Lyle -- describing them as "upstanding" individuals and saying it was an amazing experience to be in their company.

Cooper told Variety the instant vibe between him and Erik was sparked by a phone call they had before meeting up ... saying he reassured Erik he was all about portraying him authentically in "Monsters: The Lyle and Erik Menendez Story."

During that phone call, Erik first opened up about his criticisms of the show ... so seems like Cooper and the show crew weren't exactly blindsided when Erik aired his grievances publicly.

Cooper says he totally gets where Erik was coming from ... especially since no one wants their most traumatic moments turned into a Hollywood drama.

CK's also throwing down some serious claims, saying the Menendez brothers deserve a retrial -- pointing to a mountain of new evidence about "child sexual abuse and male-on-male sexual abuse," Cooper says, that’s come to light 35 years after they got life sentences for killing their parents.

As for the show's director, Ryan ... he’s heard Erik’s critique loud and clear. He’s a little puzzled, though, since he knows the brothers haven’t even watched the series yet -- but he’s encouraging Erik to give it a watch, claiming he'd be super proud of Cooper’s performance.