Britney Spears revealed she had an abortion while she was in a relationship with Justin Timberlake, calling it “one of the most agonizing things I have ever experienced in my life.” Brit opened up about the decision in her new memoir, The Woman in Me. The two stars started dating in 1999 when Spears was 17 and Justin was 18, with their relationship ending in 2002. Spears says that her decision to have the abortion was because JT didn’t want to go through with the pregnancy. “Justin definitely wasn’t happy about the pregnancy,” she alleges. “He said we weren’t ready to have a baby in our lives, that we were way too young.” She added in the book, “I don’t know if that was the right decision. If it had been left up to me alone, I never would have done it. And yet Justin was so sure that he didn’t want to be a father.” Spears’ new memoir will be out October 24.