Article continues below advertisementRob Reiner allegedly opened up about deep fears involving his son Nick Reiner just hours before his shocking death.Article continues below advertisementAccording to a well-known Hollywood friend, the legendary filmmaker shared his concerns while attending Conan O'Brien's holiday party on December 13 - the night before he and his wife, Michele Singer Reiner, were found dead."I'm petrified of [Nick]. I can't believe I'm going to say this, but I'm afraid of my son.