'Lost's' Man in Black -- No Alternate Endings!

5/18/2010 9:15 AM PDT

'Lost's' Man in Black -- No Alternate Endings!

"Lost" star Titus Welliver plays the show's mother killing, shapeshifting, "Man in Black" -- but  yesterday in L.A., dude told us the finale wouldn't be changing form ... because they didn't shoot any alternate endings!

After explaining how his real mother "wasn't bludgeoned with a rock" -- phew -- Titus (who's the nicest guy ever btw) settled rumors about a potential "Lost" movie ... and promised us that fans wouldn't be "disappointed" with the way the show ends.

The last 60 minute episode airs tonight -- followed by the two-and-a-half hour series finale on Sunday.

Don't worry, our "Lost Diary" guy is already stocking up on the Red Bull.