As told to Laurie Sandell by Kim Kardashian

Several months ago I was in the news for weeks because a sex tape I made with my ex-boyfriend, [the R&B singer] Ray J., was broadcast over the Internet and distributed on DVD. I’m not going to try to defend myself—I made the tape, so I have to deal with the consequences. But I do want to tell you what it’s like to have your most intimate moments scrutinized by thousands; to have your stepfather refuse to speak to you for weeks; to be forced to explain the term “porn star” to your nine-year-old sister.

I grew up in a very different kind of spotlight: My father was Robert Kardashian, one of O.J. Simpson’s attorneys. When I was 10, my parents divorced and my mother married the Olympic decathlete Bruce Jenner. There were four kids in our family and Bruce had four, so when the Jenners moved into our house, my life changed overnight. Seeing my family break apart like that—and having a new one form in such a short amount of time—made me long for stability. So at 19, I eloped to Las Vegas with my boyfriend, [music producer] Damon Thomas. I was incredibly naive. I thought I could re-create the family I wanted—and this time, it would be perfect.

My father was furious and told me I was cut off. Later he did come to accept my husband, but the marriage didn’t last: After three years we split up.

Right in the middle of my divorce, my dad got sick. I remember we were eating at our favorite hole-in-the-wall Armenian restaurant in L.A. My dad kept having to go outside because he was having trouble swallowing his food and didn’t want us to see him choking. When he went to the doctor, they told him he had a tumor at the bottom of his throat that was so big it was preventing his food from going down. The doctors wanted to remove a piece of his esophagus, but by the time he went back a week later, there were so many tumors, there was nothing they could do. I was traumatized: I loved my father so much, and my family and I depended on him for everything. He was even handling my divorce for me.

One day I ran into my old friend Ray J. I had known him since I was 16 and was friends with his older sister, [the singer] Brandy. He was funny and silly and took my mind off everything. From that moment on, we were inseparable. When my father passed away in September 2003, just six weeks after his diagnosis, Ray became my refuge: We traveled to Hawaii, Mexico and all over the world. I had just gotten a brand-new video camera, so we documented every moment of our trips. We filmed ourselves at the beach, sitting on airplanes and eating in restaurants. It was lighthearted and fun and exactly what I needed at that moment.

One night we were in our hotel room and we decided to make a [sex] tape. We were totally kidding around. I was saying things like “I need to do my hair andmakeup!” Never in a million years did I think the tape would be seen by anyone but us.

Three years later Ray and I broke up. I don’t want to go into the details; we just grew apart. I moved in with my mom and he moved in with his sister, and all of the stuff from our house went into storage. The tape was in a camera bag; I forgot about it. In December 2006 I was traveling in Australia with Paris Hilton—we’ve been close since preschool—when I got an e-mail from a friend that said, “Oh my God, look what’s online.” I couldn’t open the link, which was entitled “Sex Tape/Ray J.” I flipped out and started crying hysterically. It turned out the link was just a blind item on a gossip website that said, “Which R&B singer has a sex tape with a Hollywood socialite?” So I stopped worrying about it.

Two months later another friend paged me, saying, “Someone bought your sex tape—there’s a clip online. It’s all over Page Six.” I don’t know how, but clearly the tape fell into the wrong hands. The rest of the day was a blur. I frantically tried to get ahold of Ray while fielding calls from my mother, who wouldn’t stop calling. Although I was dreading it, I knew I needed to look at the clip to see what was posted online.

I tried to prepare myself—I truly had no idea what I was going to find. There had been rumors of extreme sex acts—none of which I’d done, but I knew it was possible my head had been superimposed onto someone else’s body. I asked one of my sisters to watch it first and she said, “It’s not as bad as you think.” Then I watched it. The clip I saw was fairly tame—we were fooling around with our clothes on—but still I started crying and saying, “How am I going to tell Mom and Bruce?” My stepfather is conservative, and I knew he was going to be upset. I was right: He was so disappointed he didn’t speak to me for weeks. As for my father, I don’t know what I would’ve done if he had been alive—the thought is unbearable. When my mom hired lawyers for me, I had to rehash every detail of what I’d done on the tape so they would know what they were dealing with. Imagine describing any part of your sex life to your mom. Now imagine doing that in front of a team of attorneys. I could have died from shame.

But the worst was yet to come. My mother and Bruce have two girls, Kylie and Kendall, ages nine and 11. One day my sisters were watching TV and a picture of my face flashed across the screen with the words “Sex Tape?” underneath. Kylie said, “Kimmy’s on TV!” I was devastated. These girls look up to me and want to copy everything I do. After that, Bruce asked me to have a talk with them. It was the hardest conversation I’ve ever had.

I sat down with the girls at my mother’s house and asked, “Has anyone at school said anything about me?” Kylie said, “Well…some people said some things.” Then she got kind of quiet. I pressed her and she admitted, “Some kids at school said you were a porn star.” How do you respond to something like that? She didn’t even know what the term meant. I tried to explain that Ray and I had been in love, and what we’d done was meant to be private. It was heart wrenching to have that conversation with them. Aside from my father’s death, it’s the lowest I’ve ever felt.

Now that some time has passed, I’m able to see the lessons in all of this: Be careful who you trust. Stick up for yourself. In April I came to a large settlement with Vivid Entertainment, the company that’s distributing the tape. My main goal was to stop production of the tape, and I succeeded—they can’t make any more copies. Would I erase the tape if I could? Of course. Would I change what’s happened since it came out? Actually, I wouldn’t. My 20-year-old brother has become more sensitive to women’s feelings from watching me go through this. My younger sisters have learned the importance of dignity and self-respect. And, most important, I have too.