Most likely bisexual by our standards. But they viewed relationships a bit different than we do.

Rigid "sexual orientation" is kind of a modern concept.

Greek culture lacked any binary distinction.

I'm no expert on the subject, but reading Plato's dialogues lately, the Athenians of the era just before Alexander had no preclusive prejudice for gendered relations. That said, the human demographic in Plato's dialogues is very much biased towards the upper class of society, and I believe that has always slanted towards social exception through hierarchy, with a special place for the rogue aberrant who strings the bow of dogma at the edge of the tribe.

I imagine that regardless of your orientation, if you’re a leader in that time period, you’re living with the undercurrent of “You MUST create an heir!”

Pictured: Alexander the Great announcing his victory to the citizens of Issus

Exactly, that was his brother from another, he's allowed to take his passing a bit rough

"but I gave him ALL the leeches!"