In an interview with the Guardian, Michael Douglas says smoking and drinking didn’t cause his throat cancer, eating clams did. And yes, that is a euphemism for going down on a woman. In this case, the woman most likely being Catherine Zeta-Jones. He tells the Guardian about his cancer,
“No. Because without wanting to get too specific, this particular cancer is caused by HPV [human papillomavirus], which actually comes about from cunnilingus.”
Douglas, the husband of Catherine Zeta Jones, continued: “I did worry if the stress caused by my son’s incarceration didn’t help trigger it. But yeah, it’s a sexually transmitted disease that causes cancer. And if you have it, cunnilingus is also the best cure for it.”
I’d like to think that whenever Catherine Zeta Jones wants Michael to eat her out and he doesn’t feel like it, he first silently curses her vagina and then makes weak coughing sounds. Hopefully that induces enough guilt to kill the mood.