“Oh What Fun” (** out of four) was a misbegotten holiday comedy about a mother (Michelle Pfeiffer) who feels forgotten by her family (Denis Leary, Chloe Grace Mortez, Dominic Sessa) until they notice her absence and how special she is and she returns to give them all the unified Christmas celebration they all deserve. Funny at first, with some sharp dialogue and ironic and clever touches, then turns syrupy and mundane and never fully recovers. Winning cast helps to keep this watchable but can’t make this live up to it’s title.