I pretty much 1 million percent disagree with the frog. I know she has PTSD and I'm guesing its from sexual trauma. However, I don't think its right of her to lambast you for what you did....and then forgot! (uhm frog did you miss this part?!?).....and are now owning up to.

Yes, you kissed your sister. You didn't know it was wrong, and you stopped. You have now confessed to your parents.

At this point I STRONGLY urge you to stop and think about your next move. Chances are that your sister has no idea what you did to her. On the one hand, people deserve to know what has been done to them, but on the other hand, if you tell her that you used to kiss her in her sleep, she may react VERY badly. You could essentially shatter her sense of trust in you (and in guys in general). Telling her could affect her entire life in that if she can't trust a guy, she may never be able to settle down, and so on. Yes, that's the worst case scenario, but is it worth the risk? Also, your relationship with her will be forever damaged. There may no be getting back to where things were before.

Yes, kids oftentimes do much worse. Kids play doctor. Etc.

I'm a sexual abuse survivor, and if someone kissed me in my sleep, I rather not know. No, I would not want to know. Sometimes ignorance is indeed bliss. While telling your sister may help to un-burden you, in effect you are putting the burden onto her, and in a way this is a bit selfish. I think this is something that you should work through on your own and with your parents. I am glad that your parents are understanding.

Some may say that I'm advocating that you hide the truth from your sister. But again, its not about simply hiding the truth. Its about not putting your sister in a bad place. Its about not turning her into a victim. Its about not making her feel confused, upset, ashamed, guilty, and so on.

I am also cautioning you about seeking out therapy for this as if you end up in the hands of a crusader therapist, he/she would feel obligated....or possibly in their eyes, legally bound to report this incident to social services. You may be removed from the home, it could tear your family apart and so on. Some may disagree with me, however, in our current social environment, reports like these are taken very seriously. (Heck, in my state, parents are being arrested for letting their kids go to the park!....In other words, social services sometimes acts with a very heavy hand and does more damage than good.) I'm not saying "don't seek out therapy" rather I'm saying that there are mandatory reporting laws and if a therapist feels that you are in any way an ongoing safety threat to your sister (even if you are not), the therapist is legally bound to report this to the authorities/social services.

Its a tough thing to navigate through as you have a number of things to consider in all of this, some of which are compounded by the fact that you're still a minor living at home. I wish you the best.