Mother Said So by Jocelyn Dexter

Dennis is in his thirties. He has an ineffectual father, a domineering mother, and a socially awkward demeanor. Nevertheless, he’s determined to find a girlfriend, despite his mother’s taunts that he is incapable of such a feat.

When he finds an alcoholic woman in an unconscious stupor by the roadside, recently beaten and robbed, he brings her back to his new home: the basement of a house in which he is the caretaker.
Rosie awakens to find herself in the hands of a strangely unthreatening but disturbing man: an innocent in the world around him; gentle and mild yet still very unsettling. Every evening, he returns to the family home to spend time with Mother.
What ties the twisted mother and son so inextricably together? Is Rosie’s fate sealed?
And how far will Mother go to regain her control?