Staircase Wit Edit Meaning

1.

thinking of the right answer too late; the perfect, usually piercing, riposte that you conceive only when replaying a verbal exchange later in your head

from the French l'esprit d'escalier, the witty repartee you thought of as you're going downstairs to leave

My coworker Ann had taken to calling me "Markus", which I hate. I told her I hated it, and her response was,"It's a term of affection."

I muttered something like "Well it's not".

What I SHOULD have said:

Considering her name, "OK, to cement this 'affectionate' relationship, I'll call you An(n)us."