Am I weird here?

I'm a girl and I have a sister who is 13 and I'm 17. We share a room and I recently caught her masturbating. She was really embarrassed. I sat down next to her and told her it was normal and it isn't a big deal.<br><br>Then I asked her what she thinks about when she masturbates and she told me that she fantasises about me. I'm not gonna lie, I was flattered and I have always thought it would be hot.<br><br>But is it wrong here? I know incest is gonna be frowned on but I'm just wondering, am I wrong for even considering it?