Why are those the only two options? They are not really opposites. The opposite of fighting is not fighting. You can do a lot of things and not be fighting. Same for lover. The opposite could be celibate, or lonely, or unromantic, or uninterested. Which might make you irritable enough to fight, I guess.

Why not a fighter or a napper?

A lover or a reader?

A fighter or a yoga instructor?

A lover or an accordion player?

Such a weird question.