The secret of Twilight Robert Pattinson's sex ap..

What is it about Twilight's Robert Pattinson that makes women young and not-so-young swoon?

Is it the Vampire thing? The accent? The chiseled jaw? The crazy hair?

The 22-year-old Brit has been the focus of "Twilight" fans as well as an increasingly large number of admirers who haven't seen the movie or read the book.

Here at the Cannes International Film Festival, the actor recently learned his lips are worth a staggering $20,000 after one of his smooches was auctioned off at a charity event.

So what is it that makes him one of the sexiest men alive?

Aside from being "just plain hot," Pattinson's popularity with female fans, according to costar Kristen Stewart can be attributed to being a tortured artist.

"He looks as if he is constantly agonizing over deep thoughts," she says.

Anything else?

"He's British. He's tall…And he's quite witty."

Turns out that's a perfectly devastating trifecta.