So my older sister who is about 15 yrs older than me has a different dad than me, same mom obviously. And she knows hardly anything about her real father. He left my mom before she was born. My mom told me that and that's all my sister knows. My mom tells me a lot more things about my sisters dad and her relationship with him than she tells my sister. Like my sister actually has gotten the wrong information from my grandma about him and I told my mom that and I asked her "are you gonna tell her?" And she said "no. Why should I." I think that's so wrong. No, it's not any of my business. But I think it should be my sister's business and my mom is hiding so much from her. But I'm not going to be the one to tell her. I just find it so weird that my mom is open talking about her father with me but not her, it's almost disrespectful in my opinion. What are your guy's opinions on this?