These people will have dates on a regular basis, and they may or may not be having sexual relations.
That said, the dating market for older singles isn’t all that easy. There just aren’t that many available singles our age and the ones who are available are an interesting lot (read Anne Lamott’s funny take of her year on to understand).
Its important to note that there is no great difference in the number of single, available men and women and so we don't face an imbalance. Well first of all, we have to consider social change.
The social emancipation of women has been refreshingly vital in the last 15 years.
Dating as an institution is a relatively recent phenomenon which has mainly emerged in the last few centuries.
From the standpoint of anthropology and sociology, dating is linked with other institutions such as marriage and the family which have also been changing rapidly and which have been subject to many forces, including advances in technology and medicine.