Brad Pitt is facing a stream of legal red tape in his attempts to adopt Angelina Jolie's two children - because he's not yet married to the sexy actress. It was recently announced the 41-year-old actor was in the process of filing for legal guardianship of his Mr. and Mrs. Smith co-star's adopted children, Maddox, four, and Zahara, 11 months. But his decision to adopt the youngsters will result in months of paperwork, in-home supervision and a high fee, which he could avoid if he exchanged nuptials with the twice-wed beauty. David Baum, president of the Academy Of California Adoption Lawyers, says, "This is not the easiest way of doing things. Frequently what you do if you are in a relationship with someone and you want to adopt their children, you marry them and do a step-parent adoption. There are extra requirements when you are not related by marriage to the children you are adopting." In Los Angeles County, the fees for a step-parent adoption are $775, and the process takes approximately three to six months, Baum says. But with Pitt filing as a second parent, the star, ex-husband of Jennifer Aniston, can expect to pay a home study fee of $2,950 and face far more scrutiny. The county will also seek letters of reference, which will remain confidential to protect the children.