Respectively, do assertive and compliant actions. If you get the "toll" event for example, pay them to get compliance points, or try to shove past them to get assertiveness points. This'll lead to more dominant and submissive actions as well as unlocking their respective traits after a while. At least I think it works like that.
Also, when you're having sex you could try spanking actions, asking to be more rough, stuff like that.