You've recorded several songs with Jay-Z. Are the romance rumours true?
I don't really like to talk about that. We go out together, so if someone sees us, they see us. Whatever interpretation you want to put on it, that's fine.

Do men throw themselves at you?
Guys don't ask me out as much as people would think because I've always got my bodyguards around me, which I guess is a bit intimidating for people. Guys should just say, 'Hi, how are you?' But they think they have to impress me because I'm famous, so they say really silly things instead. Then once they get to know me they're shocked because they can't believe how normal I am. People expect me to be a diva and be really obsessed with my appearance. I couldn't care less! But when people realise I'm only human I think they're disappointed.

You get to kiss Cuba Gooding Jr in your new film The Fighting Temptations. How comfortable were you with filming that?
Oh God. It's always very strange when you have 50 or 60 people there and someone is saying 'action!' and then you have to kiss and they're, like, 'Don't move too much to the left because you're in his light.' It's very awkward - a weird situation. I had to do a small, little kiss in Austin Powers and in Carmen as well. It's never comfortable.

Cuba knew that I was nervous. In fact, I was terrified, so in rehearsal he just went for it and kissed me and I was like, 'Oh my God!' So, he broke the ice and when it was time for us to do it on camera, it was okay. He helped me out a little bit so that I wasn't so nervous. I don't think it would've been good for the scene if I'd looked terrified.

Are there any other stars that you'd like to snog?
There are a couple of people. There are also some actors that I would like to work with. I love Denzel Washington and some day I want to do a movie with him because he is so talented.

What are the pressures of being in your position at such a young age?
I don't think about it... I just do my own thing. I love what I do and there are certain things that come along with it that I don't like, but it's a part of my job. Nobody's job is perfect. People are really critical in general and it's 10 times worse when you're under the microscope, so it's hard to grow up under that. But I have people who love me regardless of whether I sell another record or not.

What's the craziest thing a fan has ever done?
There was a guy who pretended to be a DJ at a local station and did a fake interview with his friend. While we were talking, I was wondering, 'Why is he asking these questions, why is he so nervous?' Afterwards, he admitted, 'I'm not really a DJ, I just wanted to meet you.' That was crazy. He'd called the label and our management and he went through all of that. He was smart.

How do you know who to trust?
I used to be really, really picky and really, really paranoid, but there's no need to be like that. I feel like I'm a good person and that I'll meet other good people... I do meet a lot of important, special, beautiful people.

Have you had to develop a thick skin in order to deal with the press?
There's actually no way of preparing someone for the things that people say. But I have developed a thicker skin. When I first started, I was 16 and there were Destiny's Child hate websites out there. That was hard for me, but because I'm very logical, I realise why people do things. It's nothing personal and even after me and before me there was the same kind of way of doing things.

Do you remember a moment when you thought, 'I've made it'?
When I saw one of our videos on TV for the first time. We were all together in the studio recording the first album. We were 15 and we'd been doing it since we were nine. We were the happiest girls in the world that day! We couldn't finish the recording session... we jumped around on the couches, jumping on each other and into each others' arms. It was like corniest but the nicest, sweetest moment. It was so wonderful.

Do you ever feel overwhelmed by everything that's going on around you?
If I feel overwhelmed, I now know my limits, and I say, 'Okay, this is how long I can work without going crazy, and this is how many days I need to rejuvenate and start over,' and I'll do that.

What do you enjoy doing during your time off?
Just anything where I can chill out, lie on the beach, and paint. I like going anywhere where there's an ocean and there's sun and nature and peace and quiet.

How do you feel about being compared to J-Lo?
People compare me to so many people. It's really flattering at times but sometimes it's not so flattering. I feel proud that I'm so young and I've accomplished so much - I'm a singer and a songwriter. I've won Grammys for writing songs, I'm a producer and now I'm becoming an actress. But I don't want to do things just because people say, 'Okay, because you sing, now do a movie.' No. I've had plenty of opportunities to star in movies, but I don't want to do it that way. I want to be here when I'm 40. I want to be here a long time. So, I'm really concentrating on the quality of the work that I do and on becoming an artist and becoming like Dorothy Dandridge, Barbara Streisand and Judy Garland and people that I respect because they're good at everything that they do.

Why are you so interested in acting?
Because it's a challenge and it's something different and I feel like I have a natural instinct for it. It's something that kind of happened to me naturally and I enjoyed it. It started off with the stability of being able to be in one place for five months, and being around people. Socially, I was never around people very much because I had tutoring since I was in the eighth grade and went to a private school most of my life with just 10 other people. So, I was never around people my age - always older people - and I was never around anyone long enough to build up a relationship. Acting's an important thing. It's like my college, and it's really nice to be able to challenge myself. When I feel comfortable and life feels predictable I don't get any joy out of it.

Have you ever had acting classes?
I've had one class! I would love to do more if I had more time. Initially I was scared to take classes because I'd heard so many horror stories about people making you be animals and all kinds of crazy things during lessons. But it was nice...

How did a part in The Fighting Temptations come about?
I told my agent I wanted to do a movie where I could be less glamorous and more natural; where I could play a real woman with regular issues that women go through. So she gave me the Fighting Temptations script and I really liked it. I thought that it was very funny and uplifting. And then they told me about the music. I heard some of the tracks, and I loved it.

How do you feel now about your unglamorous role?
That's what attracted me to the movie. I feel like it was necessary for people to see me heavier. It was necessary for people to see me with my hair twisted and not so glamorous, with no make-up on, no glamorous clothes and for people to see me dealing with real issues like being a single mother. I grew up in my mom's hair salon and I was around single mothers a lot - powerful women in general - and I could take that and put that in the character.

Is gospel music a part of your background?
I grew up in church, but my church choir wasn't that great until I was 12 and went to a different church where there was a really big choir. It was so powerful. The great thing about doing it in the movie was that it still gives me so much joy - no matter how many hours it takes. There's so much rejoicing and happiness in it.

What else do you feel you want to achieve?
The people I love and respect mix both acting and singing. In the 1940s you had to be a triple threat or you couldn't make it, and I love that, and I wish that it was more like that. I want to eventually do a musical like Moulin Rouge or Chicago and win a Tony Award and all of that!