Miley Cyrus knows the chick boyfriend Patrick Schwarzenegger hung out with and hung all over in Cabo ... because she's hung out with her too.
Her name is Natalie, and she spent time with Miley at a USC football game in November. Natalie was with a guy, who we're told is her boyfriend.
Patrick says the guy is one of his best friends so it was purely innocent when he did body shots off of her and was huggin' on her.
Miley apparently is not ok with it, based on her social media posts Monday and the video we shot at the Laugh Factory later that night.