“Cuck” (** out of four) was a monotonous melodrama about a psychologically unstable loner (Zachary Ray Sherman) who gains popularity as a vlogger but this only fuels his descent into madness and rage and escalates his progression to violence. Unpleasant story holds your attention for a little while but it eventually wears you out. Sherman ranges from effective to one-note in the lead. Legendary B-movie actress Sally Kirkland has a minor role as his mom but I doubt this is the comeback role she’s waiting for.