seeing as he had just turned 15 and was still kind of like a baby. So when I confronted my sister about it, she kept avoiding the question and changing the subject and acting like nothing happened. I was finally fed up with it so I went to my boyfriend and I asked him straight up and threatened to break up with him if he didn't tell me the truth. He then told me that he had slept with my sister and that he was in love with her. I couldn't believe what I was hearing so I ran and confronted my sister about it and she admitted. My feelings were so hurt and I couldn't handle it so I ran out of the room. I felt so betrayed and deeply hurt by their actions. When I asked them why they did it, they said that they don't know that they were just attracted to each other and that they couldn't resist. When I asked him if it was a problem with me, he straight up said to my face that I'm just not as hot as my sister and that she was prettier anyway. When I told my sister this, she just laughed in my face and said, oh well, it's not my fault I got the better genes. Years later, they ended up dating, getting married, and getting divorced.