What went on between Charlize Theron, Shirley MacLaine and Kathy Bates in room 406 last weekend? We may never know.

Just back from a Polynesian island vacation, Theron looked pretty hot in a black strapless Marc Jacobs gown as she accepted the Desert Palm Achievement Award, Actress at the Palm Springs International Film Festival awards gala Saturday.

After hugging presenter-pal Keanu Reeves, Theron peered out into the audience, asking, “Where’s Shirley? Where’s my Lady of the Night?” Spotting MacLaine, there to receive a Lifetime Achievement Award, Theron issued a tempting invite: “Shirley. Later. Room 406. You know where.”

Theron was referencing the up-close-and-personal act she performed on MacLaine at Premiere’s annual Women in Film awards last year. Theron, who was on meds for a neck injury, left the stage to literally kiss MacLaine’s behind. But MacLaine hardly seemed to mind. She bent over willingly for Theron’s good-natured butt buss and afterwards proclaimed, “That was the best I had all year!”

When Bates later presented the PSIFF award to her pal MacLaine, the 71-year-old redhead stepped up to the podium and said, “My darling Kathy. It’s room 406 for all three of us,” adding, “Hey, everyone else in this town is doing it! I don’t want to miss out,” getting the night's biggest laughs and loudest applause from the largely silver-haired audience.

Admiring the award — a provocatively twisted naked human form — MacLaine said, “Wow, this is a strange one. This ball doesn’t come out. Ve-ry creative stuff going on in the desert community."

When MacLaine mused about her long film career and many lives, she explained that she was “never very ambitious or very competitive,” to which Bates literally exploded with a loud guffaw. Bates had earlier revealed, “Shirley tells me that if I lose weight I will never work again. But I think she thinks if I ever get really skinny, I’ll be up for her parts.”

The kidding continued at the after-party at Le Parker Meridien, where the two friends held court, joined by Virginia Madsen, who had presented an award to her “Sideways” producer Michael London (“The Family Stone”) and Sally Kellerman, whose “The Boynton Beach Bereavement Club" screens next week at the fest.

No word when the gals went up to room 406.

Photo Credit: Virginia Madsen, Sally Kellerman, Shirley MacLaine and Kathy Bates have a girls' night at the Palm Springs International Film Festival awards after-party at Le Parker Meridien, hosted by Tiffany and Harper's Bazaar.
(John Shearer / WireImage)