Could it be that there is a cultural divide where things we consider homosexual they didn't?

Yes. For example: everything.

The Greeks did not have a concept of heterosexuality or homosexuality. There was merely reality: men were expected to marry and have children, but other than that, people were attracted to whomever they were attracted to, and there were apparently few limitations to acting on such attractions. We therefore have no way of saying how common homosexuality was in Ancient Greece - the Greeks themselves would not have recognised it as a distinct idea and presumably no Greek would have self-identified as gay.

Older scholarship insisted that same-sex relations in Ancient Greece exclusively existed among the upper classes and always took the form of pederastic relationships. Such relationships indeed appear to have been common throughout Greece; older men would take a teenager under their wing and teach and train him in various citizenship skills, receiving sexual favours in return. These pederastic relationships were very public. The Boeotians even had public rituals associated with the ascent of a former boy "beloved" into adulthood, when his older "lover" would gift him a suit of armour. Several couples (especially Sokrates and the young Alkibiades) were famous for the way they doted on each other.

However, there is also plenty of evidence for same-sex relationships between men of the same age, and even relationships where the older man was the passive "beloved" rather than the active "lover". We can now recognise attempts to put Greek same-sex relations in a neat little socially acceptable box as a desperate throw by modern conservative-minded authors to deal with the fact that many Greeks don't seem to have found much very abhorrent about men falling in love and having sex with other men. Lesbian relationships existed too; the poet Sappho's love poems to women may have been autobiographical.

Source: K.J. Dover, Greek Homosexuality