<human>: Can you give me a shortened version of the text?

Well I am 29 and she is 24. We started a fling outside of her  serious relationship. She happens to be the younger sister if the girl I lost my virginity to about 14 years ago. This made us both weary of starting this "relationship". I am usually very stubborn about doing anything involved with anyone in a relationship, but it seemed neither of us could stop it from happening. 

It seems neither of us can stop thinking about each other and spend every moment of free time we can together. We hang out like best friends and lovers. What I am wondering is if anyone has had a successful relationship that spawned from a situation like this. 

We both are in about the same stage of life with what we want, where we are going, and what we want from life. I know her current situation was falling apart before I came along, but neither of us were looking for anything. It just seems we both found it. I guess I just want to hear about other experiences.
<bot>: started sleeping with a friend who had a boyfriend. It has spawned feelings neither of us expected. Has a good relationship come from this situation with anyone.