Even if you're not a fan, you probably know that the movie "The Twilight Saga: New Moon" the second installment in the "Twilight" series, that opens Nov. 20, has teenage girls in a collective frenzy -- even camping out to see the first screening.
"I love the romance, vampire romance, and the possibility of being able to love someone forever," said a young woman in line to see the film in Hollywood, Calif., today.
But what you may not realize is that some of the most fanatical Twi-hards are their mothers.
"We don't act like teenagers. I mean, we are still moms, we're still adults," said Melissa Peterson, 42.
Peterson is one of more than 30,000 members of a group called Twilight Moms who don't just enjoy the story. They travel around the country for Twilight Moms conventions.
And they obsess over teen vampire love in ways that would make their kids blush.
"It's like I'm alive again. I'm awake again, you know, in all different areas of my life. It just makes you, you just feel so happy," said Sarah Clark.
"It takes you back to when you were 17 and had your whole life in front of you," added Peterson.
And Twilight Moms come in many forms. Kelly Ripa, co-host of TV's "Live! With Regis and Kelly," recently declared on-air, "I'm a Twilight Mom!"
The story of a teenage girl's love affair with a vampire named Edward Cullen, played by Robert Pattinson, has sold 85 million books and counting. "Twilight" brought in $385 million at the box office worldwide.
"Expectations for "New Moon" are to match and possibly outperform at the box office," said Variety writer Justin Chang. "It's taken on a life of its own."
Cullen's subtle style is credited with enticing some of the older Twi-hards.
"He knows how to treat a lady in a sense, and I think a lot of older women in particular, older readers, older moviegoers find that appealing. It's a cut above the average Harlequin romance," said Chang.
"This character was born in 1908, so he behaves like a gentleman and we don't do that anymore -- so it's kind of fun," said Peterson.
Fans Fall Hard for Actor Pattinson
Pattinson told ABC News that fans old enough to be his mother have asked him to marry them.
"It's strange, and it's not, really, in a kind of ironic way, as well. It's kind of like, 'ha ha, oh yeah, thanks,'" he said of his encounters with older fans.
And with more movies in the pipeline -- by the time this saga is over -- there may be Twilight Grandma conventions.