How does one become a 'sexpert'?
My agent hated the term 'sexpert', but I thought it was quite funny. My sister used to run a family-planning clinic in Australia so that made me quite comfortable with sex. The other thing was, my dad had an affair. I could see that he loved my mum and I thought what a powerful thing this is – sex and love.
Has the idea of keeping relationships like your parents' together been a motivation?
I think it has been.
Who do you turn to for advice about your own sex life?
When I first started doing this people did say: "You don't need my opinion – you know what to do". But it's much easier to look in on other people than at yourself. I have three fantastic therapist friends who I trust immensely.
It's just over a year since Fifty Shades of Grey topped bestseller lists – is the world a better place for it?
It did the world a lot of good. It blew apart the idea that women have this white knight, romantic fantasy going. No they don't! They're just as filthy as men. I actually laughed a lot reading it, though. It's like Mills & Boon with spanking.
And are the characters healthy sexual role models?
There are things that disturb me about it. There's nothing wrong with tie-up games and spanking etc, but I worry that in the wrong, unintelligent hands it might be misconstrued.
What about pornography? Is it good for us?
Yes. I get in trouble about my attitudes to porn. I know there's an awful side to the industry where you do have people being used. I'm not talking about that, I'm talking about the average porn that the average person watches. Anything that keeps your fantasy life nice and spicy will make you want to have sex with your partner – and I think that's important. It cuts down on affairs. If you can be unfaithful in your head, you tend not to be in real life.
Isn't the majority of it a pretty warped view of what sex is like?
It is. But anyone who watches porn and thinks that is what sex is like is bonkers. Maybe – and this is what I get criticised for – I assume people have a certain level of intelligence and ability to be able to see that what they're watching is just entertainment.
Are you worried, then, about young people growing up with sexual attitudes formed by internet pornography?
It's a massive worry. But we are kidding ourselves if we think they are not going to watch it. So we need to be more open in discussing it and saying to young people: "If you want to watch it, fine, but be aware that this is not a representation of real life".
Do you think that society can ever be 'too sexualised', or should we be aiming for ever-more openness about sex?
Society is too sexualised. In our society, it's all about what you look like, being sexy, appealing. But a society can be over-sexualised and still not be open enough about sex. Go to Scandinavia. They're just so open about everything – but they're not over-sexualised. You won't see kids running around looking like teenagers. It's healthy. Here it's still a bit like we're giggling behind our hands.
Is there too much sex advice out there?
Yes, there's tonnes and tonnes of it. Still, I'd rather see too much than too little. But I think we need to manage our expectations. There is a perception that if you take enough advice you will have the perfect sex life. You won't – even if you do every little thing that someone like me tells you to do, you're still human.
Tracey Cox is a sex expert and author of books including Hot Sex: How To Do It and her new title, Dare: What Happens When Fantasies Come True. Born in Exeter, she studied psychology and lives in Notting Hill, west London