And yet we have the saying "all's fair in love and war." Adultery, experienced in xx% of relationships, is a blatant power struggle. It's normal to edit your dating app pictures (or was back when people actually used dating apps) to look more attractive, or to get cosmetic surgery. There's custody battles and all that.
"Where love rules, there is no will to power, and where power predominates, there love is lacking. The one is the shadow of the other." -Jung