It's about keeping her lover insecure.
She doesn't believe in partnership. Much less the deeper fulfillment of communion. She believes in the battle of the sexes, a war she believes she'd be a fool not to win.
So she lies, threatens, refuses to commit, pulls the rug from under, insults, browbeats, screams. Whatever it takes to keep him off balance — her shallow interpretation of dominance. To her that means "victory".