American actress Jessica Alba has claimed that she had decided not to have sex until she reached the legal age.

The Fantastic Four actress, who got engaged to her Dark Angel co-star Michael Weatherly, at the age of 18, said that she was determined to remain a virgin despite being tempted to sexually experiment.

"I think I was ready to have an adult relationship when I was 16, but it's illegal in the States to be intimate with anyone over 18 if you're younger I'm someone who lives by the rules," Femalefirst quoted her as saying to Cosmopolitan magazine.

Alba also said that she wanted her first sexual experience to be with someone she was in love with, because all her friends were left disappointed by their 'first time'.

"I always knew I wanted to be in love with the first person I slept with because for almost everyone I knew, the first experience made them feel like s**t"," she said.