Aw, I was just about to say parents having love. I randomly woke up one night and I could hear.. ah I won't get into it.
Anyway, lots of stuff happened to me, ones that I will remember will probably be almost being hit by a car, being chased by the cops, and having purple balls.
Also, why would you seeing your sister masturbate be traumatizing? I'd laugh and make sure she could hear it so she would be embarrassed. :D