In RPGs, there are a couple of ways that developers have handled romances—and, specifically, sexuality within those romances. The first route is to have specific orientations for each character. For example, Zevran in Dragon: Age Origins is bisexual, whereas Alistair is straight.
The second route is to make companion characters "playersexual" ala Baldur's Gate 3—they have canon sexualities sometimes (Astarion and Karlach are canonically attracted to, at least, men and women) but they're never specifically set in stone, and will adjust to the player's interest regardless of their gender.
