Demi Moore left Chateau Marmont in Hollywood alone, but earlier in the day, Ashton Kutcher's ex was surrounded by a crowd of A-list celebs! Watch the video below.

Demi joined Nicole Kidman, Reese Witherspoon, Andy Garcia, Amy Adams, Ben Affleck and Matt Damon for a surprise appearance on Jimmy Kimmel Live. Damon took over the show as host while Kimmel sat tied up with "Loser" written across his head.

What a great way to bring even more attention to his earlier time slot!

As for 50-year-old Demi ... sucks to be heading home so late all alone. Perhaps she'll find love again soon!