Aiden Shaw, 40, is, well, a very big star. The Brit has headlined more than 50 adult films, and the HBO series Sex and the City named a character after him. He’s so big, in fact, that some retailers stock highly personal devices modeled after his anatomy. Now, he has written an autobiography, My Undoing (Carroll & Graf; $15.95), which chronicles his adventures with HIV, prostitution and drug use. Here, he previews his latest money shot.

Does having HIV make you feel less sexy while performing?
Not at all. I tested positive in the ’90s. I don’t remember exactly when. I took it for granted that I would be positive, and it seemed very natural, so I never took a hiatus from porn.

Why did you decide to go public about your HIV status?
My mother told me honesty was the best policy.

Did it become harder for you to get work?
No, because people in the industry had very little public response to my status. I’ve always made sure my partners in films know I’m positive, and I’ve never done a barebacking movie.

Why do you think such few porn stars have come out about HIV?
Because people have no guts.

What advice would you give to positive people struggling with their status and sex?
A good therapist can help you unravel your insecurities and fears. I am not a role model. I am very casual about HIV and drug use in my book, and some people have complained that I am not setting a good example. Well, I’m just telling what goes on. I’m not glamorizing it. The book shows how I’ve ruined relationships and made myself ill. It’s a mixed bag, but you can learn from what I’ve learned.

Why did you write the book?
It was an exercise. I wanted to just write what happened without any rumination or anything fancy on top. Next, I’m returning to school for a master’s in modern media art.

Do you think that the attitude toward both HIV and using condoms in porn has changed?
I think people have probably gotten more used to models being positive. But look: Some things are more vital to life than [worrying about] disease. Unsafe sex happens all the time. Some people don’t care about who’s positive. I’m partnered now, and we always have safe sex. He doesn’t want to catch it, so I don’t give it to him. It’s just a practicality.