"did odysseus cheat on penelope?" -> this question becomes more meaningless to me the more immersed i am in homer. "cheating" describes liaisons outside of exclusive relationships that are secretive and illicit because they are not socially sanctioned. odysseus, on the other hand, would have no cultural expectation of marital fidelity. in fact, he would be expected to sleep with other women. this opens up a whole new world of problematizing sexual norms in the homeric epics, so if you mean "did odysseus have extramarital sex?" that's what you should say.
"okay then, did odysseus have extramarital sex?" -> oh yeah. for sure.
"so by modern standards, odysseus cheated?" -> i don't feel that that's the most interesting way to approach the odyssey, when there's so much—
"but such a big deal is made of penelope's faithfulness! isn't it important to point out the double standard?" -> yes, i do think it is, but i also think the poem's actual portrayal of odysseus and penelope's marriage, of penelope's solitude, and of odysseus' encounters with goddesses have unusual features to them. they all show complexity within and beyond the double standard. penelope is more than a faithful woman passively waiting for her philandering husband. she schemes. she questions everything. she has things of her own to protect. likewise, in context, odysseus' (grand total of two) affairs with goddesses are less straightforward than a man sleeping his way through a lineup of temptresses. on both sides! in fact, given the way power dynamics shift in the poem, i'm wary of being too definitive about consent—
"oh, so odysseus never had consensual sex outside of marriage" -> that's not quite what i was getting at. i do read odysseus as a rape victim at the point in the odyssey that we meet him, but as i've said, his situation is unusual and not straightforward. to say he never had consensual extramarital sex is not only ahistorical (not to mention ignorant of the sexual violence conquering armies perpetrate during warfare), but also reading against the text significantly.
"if you imply odysseus ever could have slept with calypso willingly you're a rape apologist" -> this is an epic the musical fan.