"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.