After a split from my ex wife who, on the occasion we had sex, pleasure was immense . I started dating a girl who had several kids, after a short while I noticed I wasn't really getting much physical pleasure from sex and put it down to her having a stretched Vagina and she was always very wet. We learned to cope by developing increasingly kinky practices to allow for a more mental stimulation rather than relying on physical so much. Sex has always been important in a relationship to me so I started to seek other partners that might fore-fill the physical side more. I am 48 my GF was 35, the next partner was 30 years old with no kids, she also got very wet and so I put the lack of physical pleasure from her down to he being overly stimulated.. Now I am dating another lady 38 years old and in great shape. But its still the same story. We start to have sex. I recieve little physical pleasure and soon it feels like I am going through the motions and my penis starts to loose interest often I cant even tell if I'm hard or not and soon go soft. I now realise that 3 perfectly fit girls, all younger than me can't be the problem.. Otherwise I seem to be in reasonably good shape . I have no other problems with my penis and I am bigger than average in the downstairs department, with a wide girth . I know I could exercise more etc. What can I do?? It is now effecting my libido and I start to feel intimidated when I have female company as I know they expect sex and I just cant perform as I used to.