Can you be gay in inzoi

Yes. You can even start the game in a family with 2 gay man married to each others. So that's not even a question. However just like IRL, some NPC remains heterosexual, so if you try to romance them they will reject you.

Granted, it is possible to have gay Zois in your game by manually making a couple already in a relationship, but if you were hoping for your simulated characters to find same-sex.