Luciano’s initial response was because Oscar had his guards eavesdropping on the siblings and Luciano knew it. In Ines’s flashback to that scene, she noticed it for the first time. In addition, in subsequent chapters, Ines revealed that Luciano came to visit her again and gave her a bullet. He told her to use the bullet to kill Oscar. He told her if she couldn’t do it, he will do it for her. He assured her that in either case, he will take the blame. After Ines realized her brother was irrevocably set on killing Oscar, she decided to kill herself instead. She didn’t want to drag him down with her since technically she is the one who chose Oscar herself. That was her way of putting an end to the situation.

everytime I think about them two I remember he supposedly heard her being assaulted