By peoplestaff225
Updated November 02, 2009 06:30 PM

Boo to you!

Stepping out for a Halloween gala on Saturday evening, Kate Beckinsale, Len Wiseman and Lily Mo Sheen stop for a little paparazzi posing as they show off their costumes pre-party.

Lily, 10 ½, is the actress’ daughter with her ex, Michael Sheen.