If you think about replacing anyone, you really are not doing anyone a favour, and it does not bode well for a lasting relationship.
Accepted by society, yes, but acceptable?Of course, to really irritate her, you could start telling everyone bad things about her, but that would sink you down to her level, which is awful, but perfectly acceptable.
Vengeance is cheap, petty, highly self-gratifying but ultimately hollow, pointless and weak.