Billy Ray Cyrus and wife Tish seem like some pretty permissive parents. Do Miley and topless partyboy Justin share a room?

"Justin is the guy Miley's parents see her settling down with a few years down the line," a source says. “He's handsome, talented, clean-living, goes to church and knows his Bible—a real catch."

Gaston reportedly still keeps a separate apartment, but seems to spend most of his time at the Cyrus residence...which would supply him with hot and cold running Miley whenever he wants.

"Billy Ray wasn't born yesterday," a source says. "He figures the safest path to take is to keep Miley and Justin on a short leash—and under the same roof."

Riiiight. Because teens have never been known to creep down a hallway at night...