Directed by Roger Michell of Enduring Love, The Mother is a fascinating and frank look at an older  woman's sexual awakening, and the havoc it causes in her already dysfunctional family.  

May is played brilliantly by the talented Ann Reid, recently in Savage Grace, and Daniel is Darren, the married boyfriend of her daughter Paula.

When May and her husband visit their grown children in London, he suddenly has a heart attack and dies, leaving May adrift for the first time in her life.  Unwilling to return home and vegetate, her busy son and his wife reluctantly let her stay in the spare room temporarily.  She seems like a sweet grandmotherly type, but clearly the kids have issues with Mom.

Darren's a bit of a womanizer and slacker, but he's been contracted to build a conservatory addition to their posh  home, so he's around during the day.  At first May doesn't like him and urges her daughter to find someone more suitable, or at least single, but he's charming and sympathetic, and seems genuinely interested in what May has to say, unlike her family.  They eventually form a bond of sorts, as they're both outcasts.  When Darren takes May out to lunch one day she impulsively kisses him.  He responds, but she's embarrassed by her behavior and runs off quickly.

During the day she tells him about her life as a bored but dutiful spouse while he pounds nails, but the sexual tension is building faster than the conservatory.   Pretty soon he's pounding her in the spare room and his expert sexual skills unleash her inner animal.  Their torrid affair is complicated by his ongoing relationship with her daughter Paula,  his never-seen wife, and his increasing drug usage.