An example: Once when I was cuddling and talking with my (now ex) girlfriend in bed, she randomly became emotional and tearful. I asked her what was wrong, and she told me the thought of me potentially getting another woman pregnant was making her really upset. She made me promise that she would be the only woman to ever give birth to my kids, and that I would get her pregnant within the next 2-3 years.
Our relationship ended some time after and it never happened. She had a kid with another guy later on. But what she said that night made me feel an intense feeling of love & being desired that I've never felt since.
Have you ever been told something during sex or intimacy that has remained in the back of your mind?