@Magnus phil,
We know several things about Sokrates. First he was married (Xantippe was said to have been a shrew). Second, from the narrative of his life at the end of the Symposium, we know that he had (and at least one time rejected) younger and eager male lovers.
We also know several things about Attic Greece (and indeed most of the Mediterranean world---Hadrian had his Antinous) during the classical period. It was fairly common and acceptable for men to have a male lover as well as a wife at home to run the household. Given the political structure of the polis, it was useful to have important and strong associations outside of the family or clan, and same-sex male bonding provided just such a link in male-dominated society. Moreover, the sexual nature of the relationship paralleled a mentoring relationship in which younger men were introduced to political and intellectual life. The relationship was part finishing school and part mentoring (forgive the pun, but this was an earlier example of the "old boy" network).