Lauren Conrad is in love -- and shouting it from the proverbial rooftops! The former Hills heroine formally declared her affection for boyfriend William Tell on Twitter, calling him her "love" in a romantic tweet.

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On Thursday, Feb. 7, the 27-year-old Paper Crown designer sent a sweet -- and very public -- birthday wish to her beau of nearly one year. "HAPPY BIRTHDAY to my love, William Tell!!!" she wrote, linking to an Instagram photo of the University of Southern California law student, now 33, as a little boy.

Conrad and the ex-Something Corporate rocker began dating on Valentine's Day in 2012. Speaking about Tell in a recent interview with Lucky, she said she was drawn to his laid-back style. "He's just a jeans and T-shirt guy, which I like," she told the mag. "[But] sometimes I'll buy him clothes and sneak them into his drawer!"

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Incidentally, one hour after the star tweeted her birthday wish to Tell, Baby Daddy actress Chelsea Kane posted a similar message -- to Conrad's ex-boyfriend Stephen Colletti! (Kane, 24, has been dating the Laguna Beach alum, 27 today, since early 2011.)

"Happy birthday, Kid Colletti!" she wrote. Like Conrad, she also included a snapshot of her love as a kid -- an adorable kid, at that, in suspenders and a bow tie with a Big Bird stuffed animal in his tiny hand.

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Conrad famously fell for longtime friend Colletti when they were in high school and starring on MTV's Laguna Beach together. She later moved on to romances with Jason Wahler, Brody Jenner, and My Boys actor Kyle Howard before finding love with Tell.

This article originally appeared on Lauren Conrad Wishes Boyfriend William Tell a Happy Birthday, Calls Him Her "Love"