LONDON -- Working with Robert Downey Jr. is apparently a lot like being married to him.

"He's just a little nutty, but he keeps things fresh," says Susan Downey, one of the producers of Sherlock Holmes.

And the Iron Man star's recollection of the working conditions?

"Intolerable," he faux-gripes. "There was a lot of den-mothering going on during this process. Sometimes us fellas would be having too much fun ... But early on she was having some stomach problems, I don't know if it was the milk or whatever."

Her response? "You see this," she says to assembled journalists, "this is what he's like."

Susan was instrumental in aligning her husband with director Guy Ritchie. She had just produced Ritchie's RocknRolla.

"A movie takes so much time out of your life, and so much energy, if we can find a way to do it together, it's certainly our preference," she says. "I'm sometimes worried for people like Guy or Jude (Law) who have to be with us all the time because they see more than they need to see."

Sherlock Holmes opens Christmas Day.