Thanks for the input.. it is good to be able to talk about this.

The decision to end the old marriage was mine as I had already met my new wife.. the sex with my new wife was good for a while when we first met but I think back and the attraction is more "like minds" and similar lifestyle, goals etc. Problems really began once the initial flush was over. I didn't sleep with my ex until well after the desire had wained with my current wife

My ex and I always had a very good sex life and yes there was the odd occassion were I had problems but they were usually ill health or tiredness... and very very rare. In some ways I still have feelings for my ex.. we share the same quick sense of humour.. the ole quick glance and we knew what the other was thinking etc