My sister and i grew up with a pair of a****** abusive parents. She is two years older than me, we are both in our 30s now. We were fortunate enough to be foster homed together by a well to do couple that was kind to us but fought like cats and dogs. As we grew up we realized that despite being well cared for we were actually also an easy tax write off for them. We were both sent to college fully paid for and got great jobs. Despite graduating two years before me she stayed with me until I was out and employed. We went from abusive parents to kind but detached foster parents. We never learned what normal dating or relationships were. So we stayed together because we trusted no one except each other. We have lived together as a couple ever since. We are not really lovers and have never had s** in the conventional sense. But we know each other to the core. As a result we effectively live in a two way dom sub relationship where we are each strongly sadistic and masochistic, and trade off alternating weeks of who is dom and who is sub.