I'm going to lose my temper at my ex-boyfriends ex
Why are you going to lose your temper at your ex-boyfriends ex?
Because she's an annoying person that deserves to be yelled at for being so annoying. I hate her.
She is so far removed from you there's no reason to yell at her. How often do you even have to see your ex's ex?
I don't have to treat someone nicely if I don't like them.
Yelling at someone is rude. Can't you just avoid her completely?