'Pretty Little Liars' not just for teens

In late August, the hashtag #RIPMona became a trending topic on Twitter.

It spawned tribute photos on Instagram, "In Memoriam" montages on YouTube and a nation of tween girls screaming "Noooo!" at their television. For fans of the ABC Family teen mystery drama Pretty Little Liars, this was routine Tuesday night hysteria going viral across multi-platforms.

Pretty Little Liars, which returns for its fifth season on Tuesday, is based on a bestselling series of young-adult novels. Both the show and books take place in the make-believe Main Line town of Rosewood, with sporadic references to South Street, Rittenhouse Square, and hoagies. The story focuses on Aria, Hanna, Spencer and Emily and their quest to uncover the identity of A - a murderer, bully, and frenemy who anonymously torments them through text message. Thanks to A's antics, these teenagers are victims of enough violence and tragedy for a lifetime of PTSD psychotherapy.

Liars basks in twists, cliffhangers, and loopholes. The fans of the show, typically high school age and younger, have taken to Twitter, Snapchat and YouTube to unveil conspiracy theories and share their real-time reactions to an episode's most suspenseful moments. (Google "PLL fan reaction videos.")

Though the younger viewers of the show are more public (and a lot screamier) about their fandom, there is a secret society of Generation X and Y-ers who are also hooked on the show, thanks to Netflix and its era of binge-watching. These women, closer in age to the actresses portraying the characters, engage with the Liars franchise in a more covert fashion.

"My sister-in-law had been watching since the beginning and insisted I'd like it," says Melissa Villa, 36, an interior designer living in Bloomfield, N.J. "Then my 27-year-old co-worker lent me the first three seasons on DVD and I was hooked straightaway."

Villa prefers to remain discreet about her obsession. "I definitely have YA books in heavy rotation," she says. "I thank my iPad for tricking my fellow commuters into thinking my intense focus is on Ulysses or Walden."

"I only watch the show when I'm completely by myself in the house," admits Carolyn Huckabay, 32, a nonprofit administrator and South Philadelphia resident. "My husband won't tolerate a second of PLL. He calls them the 'Privileged Little Squeakers.' "

Theater artist and Fishtown resident Martha Stuckey, 27, thinks it's fun to fan out amongst friends. "Sometimes my friends and I text message each other with fake 'A' texts."

"My level of fandom is embarrassingly intense," admits 26-year-old Shannon Caulfield, a communications assistant from Runnemede. "This Halloween, I dressed as Hanna from the Season 2 midseason finale. No one understood my hyper-specific costume."

In the last five years, Forever Young Adult, a website that features book reviews, show recaps, and think pieces for "YA readers who are a little less Y and a bit more A," has made it socially acceptable for grownups to geek out like their tweenage counterparts.

Sara Shepard, author of the Pretty Little Liars books, spent her teenage years in Downingtown. Shepard, 37, and a devoted viewer of the TV series, is not a bit surprised that there are fans closer to her age. "Once people realized there is merit in YA, just as much as adult fiction, it became less of a taboo," she explains.

Catie Gliwa and Alexis Gunderson write weekly episode recaps of Pretty Little Liars for Forever Young Adult and run a fan Tumblr for the same demographic. Gliwa, 26 and Gunderson, 28, who co-write articles from opposite coasts, provide detailed play-by-plays that express both a sincere love of the show as well as the sophisticated wit and wisdom more likely to be found in the New Yorker "Shouts and Murmurs" column.

Both women are candid when it comes to their love of the television series. They also enjoy having adult fans of their own. Gliwa observes that there is "this little coven of commenters who are more on our page."

Gunderson has a mission to spread word of Pretty Little Liars across all age groups: "I tell everyone to watch it. I have exactly zero time for pretending not to like things that are good just because of how it might look."

She often quotes a well-known C.S. Lewis passage that shares this exact sentiment: "When I was ten, I read fairy tales in secret and would have been ashamed if I had been found doing so. Now that I am fifty I read them openly. When I became a man I put away childish things, including the fear of childishness and the desire to be very grown up."

Gunderson hopes to disseminate Lewis' message through her writing with Gliwa. "There shouldn't be a struggle, because to be adult is to like what you like. And, look, everyone in the world is a teenager at some point."

Pretty Little Liars

8 p.m. Tuesday on ABC FamilyEndText