Uh-oh, seems like some trouble is brewing in BFF-land. Singers Katy Perry and Rihanna have been tight-knit for years now, but a new decision made by Rih is reportedly driving a rift between the two. Word on the street is much like Rihanna’s boss/mentor Hovito, Katy is not happy to see Rih run back into the arms of Chris Brown. “They’re barely talking and ever since the couple reunited, there has been tension between them,” a source in Katy’s camp revealed. They haven’t been together since the VMA’s earlier this year, with Katy noticeably absent at Rih’s big Halloween party and vice versa for Katy’s birthday bash. Though that could be blamed on scheduling conflicts (as Rih even had to miss Katy’s wedding in 2010!), there could definitely be some issues brewing! Let’s hope they get through it as clearly as the gallery will show you, they make the cutest besties!