It might surprise you, but breaking up with your best friend is actually more traumatic than calling it quits with your boy.
Professor Carol Smart, a sociologist at Manchester University, has found that the ethics of friendship - particularly between women - are so rife with politics that we feel incredible guilt about ending them, even when we know it's the "healthy" thing to do.
It's something these celebrities would be pretty familiar with - they've all split from their besties.
Paris Hilton and Nicole Richie
The reason the two life-long friends parted ways back in 2000 has never officially been confirmed, but Paris did offer her two cents about the split.
“When I brought her on my show she just got very jealous and turned on me for no reason,” Paris said.
“I think she just can’t stand being around me because I get all the attention and people don’t really care about her,” she added.