Reluctant Mistress, Blackmailed Wife by Lynne Graham

Single mother of twin boys, Katie didn't want their father, Greek billionaire Alexandros Christakis, back in her life. But poverty pushed her to ask for his help. Alexandros demanded that Katie marry him. They had nothing in common--except their mutual burning sexual attraction, but resistance was futile: both the twins and Katie needed Alexandros. She would submit to becoming his mistress...