David Klass: You Don't Know me [2001] hardback

Fourteen-year-old John lives with his single mother and her boyfriend, a man who is violent towards him whenever John's mother is not around. John believes that if he tells his mother about the abuse, she will side with "the man who is not my father". There's a lot of pain, but also humour too, and horror in this book before John resolves his relationship with his mother and lets her begin to know him.