Sasha Pieterse and Ashley Benson Sasha Pieterse and Ashley Benson

She's mean, manipulative... and dead. But as fans could tell from last night's episode, Sasha Pieterse is having the time of her life playing Alison DiLaurentis.

"It's so much fun!" the bubbly 15-year-old told the Watercooler during our visit to the Pretty Little Liars set, where we got to see her in all her mean-girl action. "She's the one you hate to love and love to hate. As much as she drives you crazy and tortures the hell out of you, there is something about her you like.  There's an intrigue there. She's not mean all the time. "

True, but she's definitely messed up. And even though we only catch her in flashbacks (like that nasty one of Ali taunting newly returned brother Jason), Pieterse — who's been acting since moving to the U.S. from South Africa when she was barely 4 — promises that we'll be seeing more to Ali than just her evil side.

"[Ali] is damaged, she has a troubled background and that is something we're slowly touching on," she teases. "The girls are starting to look back on that, and they're starting to remember things... there was a lot she hid from them."

Hmmm. Sounds like Aria and company's not-so-dearly departed bestie went to her grave with more secrets than just what's already been dug up. Have any theories about what they may be? Share in the comments below!

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