Thanks for the replies. She has stated that they were friends before the sex buddy thing. Talking to each other about relationships and such. I realise that by me taking issue with it, it's uncomfortable for her as I would be essentially asking her to stop contact with a friend. She has brought up about me living with her recently so perhaps I am reading too much into it. It does still niggle me. I worry that if we have an argument she may take comfort in him. Though apparently their communication isn't even weekly so again I may be a victim of my own insecurity. She has said time and again how important trust and truthfulness is in a relationship so I guess I should be giving her a break. Doesn't help with my feelings though. I need to get over it