Actress Jessica Alba was bullied and branded a "slut" when she was in school after developing her full bosom at a young age. The actress revealed that the main culprits were her classmates' "self-righteous" mothers and her elementary school principal, who made her life miserable. Writing in 'If I'd Known Then' a forthcoming book of essays by female celebrities Alba writes: "The accusation still ricochets. They think I'm a slut?'" Revealing her first kiss at the age of 7, Alba also handed out advice to teenaged girls, urging them to have safe sex. "Boys are awful. They are made of nothing but hormones until they're about 20 or 21," she wrote. "It's fun to have a crush, but don't think it's forever," she added. The essay collection, set for publication this spring, features letters by famous women, 35 or younger, written to their younger selves. Contributors include Olympic soccer gold medallist Julia Foudy, activist Zainab Salbi and actress Danica McKellar.