I would talk to my sister. I'd probably also let my parents know about the incident and that you've handled speaking to you sister. You sound like you're very caring; your sister is lucky to have you.
If she didn't really get a whole lot of "visual goodness" then you can probably downplay it and explain to her that you were making out or something less serious. Then, take her with you and tell your parents that she saw you making out with your boyfriend, and you wanted to show her that it was wrong to break your parents trust and that you will be punished for it. Your parents won't be happy, but you will have done a good thing for your sister (and maybe get a lesser punishment).
Oh and... oooooooh you're dirtyyyyyyy.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.