Justin Bieber's Dumb Friend -- STAGED Selena Gomez Hookup Pics

BUSTED!!! Justin Bieber's freeloading friend is NOT hooking up with Selena Gomez, even though he went to Herculean lengths to make it seem that way ... and we have video proof.

King Kevi -- who became famous-adjacent recently by living in Justin's house and throwing ragers with lots of girls, bongs and beer -- caused a stir when these pics (below) surfaced, showing the fake royalty appearing to leave Selena's San Fernando Valley estate Saturday night.

Various media reported Kevi -- the up-and-coming nobody -- was inside her house and "hung out." But we got our hands on surveillance footage taken the night in question ... showing Kevi posing in front of Selena's house while camera flashes went off ... but never making it past the gate.

Selena wasn't even home at the time the photos were taken.

In other words ... it was all a setup by the guy who is mooching off the Biebs.

He's no Kato Kaelin.

2:45 PM PT -- King Kevi tells TMZ the whole thing is a simple misunderstanding -- saying, "I was there to drop off something to a friend at the party. I walked multiple times to the front gate to try to call my friend and every time I had to chase off the photog."

He adds, "After the last attempt, I went to my car to leave and that's when my friend called me to come inside. When I backed in, I gave him another call to open the gate and he didn't pick up so I left because I saw the photog come back around."