"Possibly" mean? O_o I don't see that kind of thing as "inconsequential"; when someone betrays you that deeply they have likely wrought very serious negative consequences in your heart, mind, and life. That is the definition of a consequential person.
Sorry if I sound harsh, but I have absolutely no respect for those who cheat on people they supposedly love. When people betray that sort of trust they show what kind of uncaring souls they truly have. They crush psyches, rip families apart (if such are involved), and destroy lives.
I stand by the word "slut" for occasions such as this; a rude, ugly word for an equally rude and ugly action.