Chris Brown's Mom -- Home Invasion Robbery Was an Inside Job

Chris Brown knows exactly who's behind the home invasion robbery because it was one of his homies -- at least according to Chris' mother.

Sources close to Chris tell us his mom, Joyce Hawkins, has been warning him for years about people she calls "no good-ass friends" -- grown men who make their living as professional hangers-on to Chris.

We're told the "friends" issue is part of the reason Chris and his mother have been beefing for years. Hours after the home invasion ... Joyce tweeted, "Watch who you standing beside."