LeAnn Rimes: Engaged to Eddie Cibrian?

Nah. They were just putting the "trick" in trick-or-treat.

Eddie Cibrian, LeAnn's live-in boyfriend, Tweeted the pic below, showing himself on bended knee, appearing to propose to the home-wrecking Shape cover girl.

Of course, the sign behind them reads White Chapel Lunatic Asylum, so that's a giveaway. On the flip side, truth is often stranger than fiction with these two.

As if Brandi Glanville needs another reason to drive drunk ...

OMG: This is Eddie and LeAnn's attempt at humor!

"They are not engaged," says a source close to Rimes. "It was just part of the Halloween fun." By fun, they apparently mean making light of the fact that their affair ended their respective marriages. Hey, whatever makes you smile.