I don't know much about Fiora's personality, aside from the fact she has a temper and is arrogant, but if in theory her and Jax were in a relationship, and some random hag, mid aged woman, much older than fiora, probably in her mid 40s, approached Jax and started to hit on him in a dirty maner with Fiora being present, what would Fiora do to the woman?
Honestly I think Fiora has better things to do than angst about her romantic options, seeing as she is one of the most powerful people in Demacia. If someone was hitting in her partner, she would not dignify them with a reaction. If someone insulted he personally, she would challenge them to a public duel to the death and kill them easily.
But the whole question is absurd, as Fiora is not in a relationship with Jax, or anyone for that matter.
