Former The Hills star Lauren Conrad has a lot to smile about this week. She celebrated her 24th birthday on Monday and her second novel, Sweet Little Lies, the follow-up to her New York Times bestselling debut L.A. Candy, just hit stores yesterday!

"I based it a lot on the emotional things you go through," Lauren explains about her main character, Jane. "There's no how-to when it comes to being thrown into this situation. There were so many moments where I was like, 'This isn't normal. This is crazy!' So when it was all done with, I though this would be a fun way to tell a story."

But the one thing Lauren wouldn't talk about today was her former BFF Heidi Montag. When asked about Heidi's 10 plastic surgery procedures, Lauren grew visibly uncomfortable. "I think it's a personal choice," Lauren says. When asked again about Heidi's revealing post-surgery pictures, Lauren responded, "It's a look."

Lauren did say she's happy to have moved on from The Hills and is currently working on her third novel.

Will you read Lauren's book? Was she right to stay quiet about Heidi's recent choices?

Photo: Courtesy of MTV