Celebrity Sibling Rivalry: It's All in the A-List Family (PHOTOS)

British singer Lily Allen, 27, is the older sister of Game of Thrones star Alfie Allen, 26. That little factoid may not blow your mind, but Alfie apparently blew his top back in March 2007 when Lily released a song about him and how lazy he is.

"When I wrote 'Alfie,' nobody really knew who I was,” Lily later explained to Pitchfork Media. “At first he was really upset about it, because he thought that I was just pointing out all of his bad points and attacking him. I thought it was really flattering. I thought he'd be really, really happy because it proved to him how much I loved him, that I care about him, and I want him to do something with his life. I suppose his paranoia — induced by smoking so much weed — made him think, 'Why are you trying to be mean?'"

It appears Alfie has gone out and done something with his life... if becoming a regular on Game of Thrones as Theon Greyjoy qualifies as “going out and doing something with your life.” (It does to us.)

So forgive and forget? "All sisters exaggerate," Alfie said, smiling, during a 2008 interview with the Daily Mail. "Let's say that elements of it were true, but it concerned a part of my life that was private and I didn't want people to know about.”