The two artists just announced that they'll be going on separate tours in 2013. This is surprising considering the huge success they had when they collaborated on an album called Watch the Throne in 2011 and performed together on a tour and at major events like the Grammys.
It's possible that the separate tours show that the two once rock-solid friends have grown apart. 43-year-old Jay Z's megastar wife Beyonce reportedly doesn't like Kanye's girlfriend Kim Kardashian and has turned down Kim's attempts at friendship.
It's also likely that the two guys need more room for their entourages on the road now that their families are growing - Jay Z and Beyonce are parents to Blue Ivy Carter, while Kanye and Kim just welcomed daughter North West.
This isn't the first time Jay Z has dumped a friend following a musical collaboration. In 2002, he teamed up with R. Kelly for an album called Best of Both Worlds. Though they were supposed to go on tour together, stories began to break about R. Kelly's inappropriate relationships with teenage girls and Jay Z ditched his pal.
Either way, it's unlikely either musical megastar will have problems bringing in their fans. Kanye just made history with his seventh performance at the MTV VMAs, and Jay Z's new album Magna Carta Holy Grail has already gone double platinum.