Robert Downey Jr. has officially left the Alfonso Cuaron 3D sci-fi thriller Gravity, for which Sandra Bullock is still in talks. The Heat Vision blog reports that the actor has now turned his sights on Fox's How to Talk to Girls.

HV sources say the actor is circling the adaptation of a book by a 9-year-old boy, which offers advice on how to deal with the opposite sex. Downey and his wife and producing partner, Susan Downey, would produce with Shawn Levy and his 21 Laps banner.

Per HV, Girls was written by Alec Greven, then 9 years old, as a school project. It landed the boy a publishing deal and put him on talk shows across the country. 

Susan Downey will spearhead development -- a script draft already exists, but it is said it'll now be fashioned as a Downey vehicle.

No deals have been made with the Downey camp and insiders cautioned HV that Downey is only eyeing Girls. He's still attached to Oz: The Great and Powerful at Disney.

Meanwhile, HV says Warners will likely recast the character Downey would have played in Gravity -- who only appears in the first act.

SlashFilm surmises that scheduling became a factor in Downey's decision to leave Gravity. Per /F, the idea had been for the actor to shoot some of Sherlock Holmes 2, then break to shoot his brief bits of Gravity, then go back to Sherlock. Further, the shoot for The Avengers is on the horizon for early next year.

Source: Hollywood Wiretap