I did this too and addressed it in therapy and in here. My answer was that while the sexual abuse was going on, I got that person's full attention. I got "stroked" emotionally because I felt I did not get the healthy affection that all kids should get. Loved just because they are them. That is why I did it. Now that I know this, I do not have to do that anymore. I hope that you will be able to work through this and find your reason for what happened. I feel a lot more empowered now that I know that I deserve healthy interactions with people that have by best interests at heart. They are out there. It is about making healthy choices. Best of luck to you on working through this. Let me know if there is anything I can do to help.