Weeks back I told you how my reporter eavesdropped on MILEY CYRUS rhapsodizing about steamy trysts with hunky “Hunger Games” fiance LIAM HEMSWORTH, giggling about how they love dreaming up bizarre new places to have sex, right?

Well, I’ve zeroed in on their latest hot location: CYBERSPACE!

Backstage at iHeartRadio Music Festival in Las Vegas, stagehands stood stunned as loud, sexual moanie-groanies emanated from Miley’s dressing room, escalated in volume – then ended abruptly in a muffled shriek!

Puzzled because they knew Miley was flying solo – Liam’s been filming his “Hunger Games” sequel in Atlanta – the stagehands held their breath moments later as one guy knocked on her door to announce she was due onstage.

Opening up, Miley spotted his red face – and giggled. “Oh, sorry about all the noise,” she said, pointing at the phone next to the bed.

“My honey and I were just cyber-sexing.”