"knee deep in
ass", "knee deep in my/your/his/her/their
ass"
To get knee deep in someone's
ass is to deliver an extensive verbal reprimand with such fervent displeasure that the recipient feels violated.
see also called out on the carpet
That
text was probably an accident, but I have to uphold my authority, so I'm gonna get him in here to get knee deep in his
ass (knee deep in
ass) over it for the next hour.