I just decided to get rid of the companions quests so I started the Silver Hand. Not really hard at level 28, after the ceremony I went to aela and killed the silver hand so easily. Now She gave me a mission to avenge Skjor.
Just to make sure I did not forgot everything important in the mission, I consulted USEP and the elder scrolls wiki.
They are claiming that for this mission my follower will split from me. But my follower stayed with me and I had in fact two folloers, Serana and Aela.
Is it something to do with Serana ? (She wont quit me now because I have two dawnguard mainquest active)