One time cuckold

In a sense, it was an attempt to reassure her. We had met through an online dating website. I was into her from the first time we met. She was petite, with curling dark brown hair, a white complexion, and full breasts which her black blouse set off perfectly. It was after our third date that she came back to my place, and we made delicious love together.
Afterwards we talked, and she told me that her last relationship had broken up because her guy had started seeing someone else behind her back. Because of that, she was not sure that she could trust another guy very easily.
While we were talking, her head was on my shoulder, her full breasts on my chest, and her hand was slowly stroking my cock, making it hard again. I reassured her that I had never cheated on any woman I had been involved with, totally true, and that she was all the woman that I wanted. To make the point even more strongly I added that I would still want her, even if she slept with someone else.
It was not something that I had planned to say, or had thought through. It was instinctive, and it was more about making her realise how much I wanted her than about being turned on by her being with another guy. But it became something that I repeated, and she started saying that she might take me up on my offer. Just talking about it proved to be a serious turn on, making me hard, and if she said anything about it while we were making love, it would make her fuck her even harder, which she enjoyed.
A couple of months into our relationship, she mentioned a guy called Paul. He was a former colleague, from a previous job that she had had. They kept in touch, meeting up occasionally as friends. What she said, while we were in bed together, was that if she decided to sleep with anyone else, she would want it to be him.
Again, she was stroking my cock while she was saying this, and it hardened even more. I moved between her legs, sliding into her easily, her pussy already wet, and started fucking her, telling her the one condition I was placing on her was that she told me everything afterwards.