what should I do

there is a jerk in my team and he complain to my boss (female) that I am not back up for hime 100%

and my boss meet with me last week to discuss it. Now, this jerk not coming for whole week and

my boss requir me to cover all his work when he is not here. I informed my boss that I am going to talk with him tomorrow and invite her to have meeting together, but she don't want be part of it.

what should I do?