He had a drink with some mates on Wed evening after the gym. One of them is same age as me (43) but his birthday had been earlier that week. He told DH that it was the first time he had had no cards from women (apart from his mum). He's played the field to spectacular effect over the years and had only one significant relationship. Now his field-playing days appear to be over and there is no-one in his life. And what seemed to upset him more, no children. All of DH's other friends are with someone and have children. It's finally struck him that he's on his own. Of course there's still time but unless he meets someone much younger presumably children are unlikely.
It made me feel very fortunate.