Reaper by Nia Farrell

Maureen “Mama Mare” McLanahan is the mother of five grown children and married to Patrick “Papa Bear” McLanahan, President of the Avenging Angels MC. For twenty-eight years, she has kept secrets that could shatter her marriage and ruin their lives. No one knows that her oldest son might belong to Reaper Rhodes, President of the rival Blackwater Demons MC.
Reaper has been obsessed with Mare since high school. When his collection crew brings back her daughter Rose as a party favor, he decides to save her for his son. The next girl kidnapped has a mob boss uncle. The Visconti crime family joins forces with the Angels to rescue both girls.
Reaper’s son is killed in a retaliatory strike by the Viscontis. Wrongfully blaming the Angels, Reaper kidnaps Mama Mare to use as bait, with plans to kill her daughter. Mare is rescued before that happens but Reaper escapes. She spends the next three years fearing for her daughter and struggling with PTSD from her ordeal.
Reaper eventually resurfaces with a vengeance, taking and using two more women before he’s through. His heinous acts demand justice, but whose hand will wield the sword?