A woman was talking and a man was listening to her.
When she had been speaking for two minutes, Mr X abandoned all pretence of drinking his coffee, leaned his elbows on the desk and put his chin on his fists. And for a moment after she had ceased speaking, he
remained in that position, regarding her steadily.
Does it mean he stopped pretending that he was drinking coffee?
*Not a teacher
Yes, you are right.
abandon all/any pretence = stop trying to pretend something