Cats are such quick and fierce reactors in general that it
stands out when they show restraint.

Will and Heidi are not bosom bows, but they get along fine and
can play together some.  One reason they don't have much for
quarrels is that Will, from the first day they were in each
other's company, has refused to react to Heidi's temperamental
sallies.  She can haul off and biff him with claws extended and
his only reaction is to pull his head back and look down his
nose at her with a slightly mystified and tolerant look that
says "Now really, my dear, that's hardly called for, is it?"  It
works on Heidi just as Teti's gentle reprimand works on you --
obnoxious behavior ends.