I highly doubt Larian would 'force' your character to be lesbian. And I suppose any flirting in the game will be tongue in cheek and geared towards both sexes.
You can't compare a game like Divinity:OS to the likes of Saints Row the Third. It's not realy an RPG, it's definately not to be taken serious. And the main protagonist is angry, whatever you choose. Man, woman, or something in between (cus you can do that).
