Apropos of nothing, pretty much, "Behind the Candelabra" star Michael Douglas has decided to whip out the rather — a thousand pardons for this cheap pun in advance — tongue-wagging details on how exactly he came down with throat cancer.

In a new interview with The Guardian, he revealed that the form of cancer he was diagnosed with in 2010 was caused by cunnilingus ... which is fancy talk for oral sex.

Readers, note the date: It is not April Fool's. So, yeah.

"Without wanting to get too specific," the two-time Oscar winner said, "this particular cancer is caused by HPV [human papillomavirus], which actually comes about from cunnilingus." That seems fairly specific to us ... perhaps a little too much info in fact, though we can't help but applaud the honesty.

Douglas, you may recall, began treatment in August of 2010 for Stage 4 cancer, which he originally attributed to his well-documented history of smoking and alcohol abuse. After aggressive treatment, Douglas and his wife, fellow Oscar-winning actress Catherine Zeta-Jones, revealed in January of 2011 that he was cancer free. "That's a rough ride. That can really take it out of you," Douglas had said. "Plus the amount of chemo I was getting, it zaps all the good stuff too. It made me very weak."

Now, though, it turns out that Douglas' cancer wasn't just plain old run-of-the-mill throat cancer, but rather it was oropharyngeal cancer. And as Dr. Mahesh Kumar told The Guardian, "It has been established beyond reasonable doubt that the HPV type 16 is the causative agent in oropharyngeal cancer." In fact, there has recently been massive upswing in the number of cases involving oral sex, with more than half of the patients testing positive for HPV in one recent study of oropharyngeal cancer.

Of course, other factors — including tobacco and alcohol abuse — can certainly contribute. But as Douglas said, in his case, "it's a sexually transmitted disease that causes cancer." Pretty disturbing stuff for a Monday, but informative nonetheless. Celebs coming of the little-known disease closet, as it were, seems to be an increasing trend these days, doesn't it?

Not one to end things on too serious of a note, of course, Douglas added, "And if you have it, cunnilingus is also the best cure for it." We're pretty sure that last part was said, um, tongue-in-cheek.