A few years ago I went through a rather nasty divorce. Despite my best efforts, my marriage didn't end amicably, and it took an emotional and financial toll on me. Right about the same time, my older sister was going through her second divorce, from an abusive husband. We were close, so we turned to each other for support. She wasn't capable of fully sustaining herself, so she moved in with me. Weeks went by, and as each of our divorces went ahead, we became closer.You can see where this is going.
It was the perfect storm of being lonely and vulnerable at the same time, having an attraction, saying the right thing and adding alcohol to the mix.
We were driking wine one night after dinner, and the conversation turned to our youth. I confessed that during puberty, I had a big crush on her. She's 3 years older than me, so when I was 14 she was at the height of her youthful beauty at 17 (she's still way more beautiful than any 50 year old woman should be allowed to be: she looks 20 years younger). My confession gave way to jokes, which became more and more provocative... until I was making love to her. She would later tell me that I gave her her first orgasm in at least a decade.
We were confused by what we had done at first, but being honest with ourselves we concluded we should just accept what we desired, because our feelings for each other were genuine: we felt lust, but we loved each other a lot too.
That happened two years ago, and we've been living as a couple since. We don't have any other family to speak of (our parents are deceased, she didn't have children, and my only son lives abroad, so no need to tell his aunt and I are a couple now). We are aware it's incest and it's technically wrong, but after so many failed and even violent relationships, we cherish the only one we've ever had that is actually sincere, honest, sexy and loving.