Fifty-plus looks nothing like it used to. Fitter, healthier, many of us hit half a century with little sign of slowing down. And yet...there's no denying that something happens to us sexually at 50. The menopause brings with it a whole slew of challenges, from bottomed-out libidos to painful sex, weight gain and body image issues. Many men grapple with erectile dysfunction and the mixed blessing that is Viagra. Toss in dodgy knees, stiff backs and fatigue and sex can become a source of stress rather than pleasure. Other challenges go beyond the physical: how do you ignite desire after decades with the same person? And what if you (or your partner) simply no longer wants to have sex?