4:13 PM PT -- Miley's addressed her "morning make out session" with Cody, wondering why she can't get it in peace ... and calling the person who took the vid a "sneaky ass."
She's also fawning over the Australian hunk, saying he's her type while directing folks to his abs ... and promoting #HotGirlFall.
Miley Cyrus and Cody Simpson have been friends for years, but from the looks of it ... they're kicking their relationship up a notch.
Miley and the Australian musician/heartthrob were spotted at a Backyard Bowls eatery in L.A. Thursday being very lovey-dovey, and in a video obtained by TMZ ... they're seen gettin' in some lip-to-lip action.
We're told the two appeared to be having a pretty serious conversation before Miley moved over to sit on his lap, and before long their PDA escalated to a make-out session.
What's interesting here -- it's not the first time these two singers have been linked. Miley and Cody were rumored to be dating in late 2014 and spent a lot of time together in 2015 ... but Simpson said they were "just mates." There's more though.
Cody went on to call Cyrus the coolest girl he met in L.A. and gushed about how she's so chill and lacks insecurities. In an interview with GQ, he said ... "Miley is one of my best friends and she helps with some of that transitional stuff – trying to escape your childhood. She’s super open-minded and I’m working on becoming more like that."