RE: How do you do it?
When I am angry, I unconsciously curl my toes really hard and if I feel a strong urge to burst out, i grit my teeth or walk away. But sometimes, walking away feels worse than answering back. Know that it actually hurts whoever you're having issues with even more if you just keep quiet while they ramble alone. You might also want to try blacking out(ie attending to some more important stuff in your head. It works for me tho. If you join your rival to argue and quarrel, it would be so easy for you to become talkative or even get physical. For me, not replying makea me feel better.
Meanwhile, that story you shared up there should be enough reason for you to keep your emotions in check. ...I know it's easier said.
I really hope you find a solution that works for you.