Step one. Pull out your magnifying glass. Look closely at things like glances, gestures, and breathing patterns – pay the most attention to the details that are poky and annoying.
Step two. Run over their words and actions with a fine toothed comb. Write your interpretation on top of their words in permanent ink. If there is more than one possible meaning, choose the most personally offensive option.
Step three. Get out your big fat box of crayons. Colour the other person in. Show everyone else your picture. Be sure to point out which areas of colour are the most important.
Congratulations! You are now an expert grudge holder.