Relationships can be rough when you're a celeb, and Lauren Conrad is definitely one to attest to that. "I want to say I can always trust my good friends that I've had forever, but at the same time, some of my oldest friends have betrayed me," the Hills star tells Us Weekly. And she's not just talking about Heidi Montag! Lauren tells the mag that many of her nearest and dearest have been disloyal to her, including Brody Jenner, who went public with a new GF right after Lauren went to Paris, and BFF Audrina Patridge, who is friends with Heidi again. "Audrina has to remind me that she's not someone who's going to betray me," she says. "[And with Brody,] when you have that type of thing, you always have to question, 'Why wasn't I good enough?'"

Now, Lauren feels extra guarded when it comes to letting people into her life. "At this point, I have to question every person that wants to have a relationship with me, whether it's a friendship or a romantic relationship," she says. "It's disappointing to have to question relationships."