Non-Binary protagonist and side characters, two important female NPCs can end up in a relationship together.

A subplot deals with a lesbian relationship.

The PC can romance followers regardless of their gender. Polyamorous relationships are possible.

The PC can have Gender-Reassignment-Surgery.

The PC can have Gender-Reassignment-Surgery.

Shepard can have a relationship with a feminine-presenting, genderless alien.

Multiple same-gender romances. Both of these romancable characters are bi.

No romances, but a female PC can say that she had a past relationship with another female character.